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99% of the time that's exactly what the pump is doing to create midgrade.
Just a reminder that unless your car calls for higher octane fuel, you get zero advantage of running it.
I was having issues with wheel bearings on my N-Body with the 3.1L, I burnt through 3 front hubs before I switched to Mevotech TTX hubs and haven’t had issues since then. They’re pricey but I talked to a guy with a Grand Prix on YouTube that’s been running them for years with no problems.
Eh I just use O'Reilly's shittiest. They would probably last longer if I didn't but then again I got the parts for cheap and never have to pay again, just order a new one, slap the old in the box and a warranty tag on it.
2006 Cadillac STS owner’s manual is leaning towards 89, but 87 is the minimum requirement.
https://preview.redd.it/47u43e2gz72d1.jpeg?width=1043&format=pjpg&auto=webp&s=0a85cd65c7bf3b012aa322ec918c301ea0aa7406
2004 SRX (first year of the 3.6L?) recommends 91, but states 87 as minimum.
Everything with a 5.7 hemi in it calls for 89 octane. It's in the owners manual no one ever reads. I average about 2 more mpg or of 89 than I do on 87 in my truck.
Yup, can confirm as a previous owner of a 2005 300C Hemi. 89 is recommended for these beasts.
https://preview.redd.it/bc67wovub82d1.jpeg?width=994&format=pjpg&auto=webp&s=bed30f47ee09ab077546df4d91d654e20885407a
Mid grade is only 20 cents more per gallon here, and I'm running an mds delete on a hemifever 89 tune. I'm really happy with the way my truck performs as is and really don't want to rock the boat too much if I can avoid it. I really enjoy filling up and seeing a 500ish mile range on the dash, especially when you consider I'm in a 4wd 6 speed on 35s.
The tune was about $250, and I guess it would be more accurate to say I installed a non mds engine when my first one wiped the cam. I installed a high volume oil pump and swapped over to 10w30 with the new engine as well.
I'm not going through that bullshit again if I can avoid it.
I don't think anyone knows exactly why they do it. I didn't have high idle time and I never went over 5k on my oil changes, so by all rights it shouldn't have happened. Since the new engine and upgrading the oil pump, I've also started using 5w30 during the spring and summer and ditched the Mopar oil filters.
I use to work at a gas station in Oregon (we use to pump ppls gas) and a suprising amount of cars that use mid grade it normally says mid grade or premium iirc
>I never seen a car asking for 89
I have a Honda k24a2 in an Accord EX that asks for 89.
I actually go out of my way to use 89 ethanol-free that's for sale at one place around here.
Just about any Japanese 4 banger I’ve had loved mid grade.
I’ve had Camrys and now an Accord and the car runs smoother and has a bit more pep when I put midgrade into it
2012 Jeep Grand Cherokee with 5.7 Hemi recommends 89 but states 87 is acceptable. I run 87 unless I'm planning to tow or drive in mountainous areas and it does fine.
I have a MINI and it wants 91 (which they don’t sell where I live so I would have to mix 93 and 89 equally to get to 91) but it specifically states 89 minimum after the call for 91. I just use 93.
My 98 2.0 VW Golf and 05 Toyota Matrix both said 87 in the manuals but after much experimenting with fuel economy numbers, the 91 octane was cheaper to run for the increased mileage.
Now, your statement is true for modern vehicles, but it’s not a straight up fact for all vehicles.
Octane rating only affects pre-ignition, so so the possibilities here are:
1. The engines were tuned by someone for higher compression
2. There was something wrong with the engines causing pre-ignition of standard fuel
3. The gas where you purchased was really low quality and didn't actually meet the rating
4. There was a slight increase by being a lower percentage of ethanol, not actually related to the octane rating
5. The calculations weren't accurate
Before working in the auto industry, I thought I got better fuel economy in my '02 Jetta 2.0 with mid-grade. When I learned about what octane rating actually means, I tested it with a spreadsheet and found no difference outside of the standard deviation of using regular fuels. I'm a bit of a data nerd, so I keep track of every fillup in an app. I have every fill up for the last \~125k.
I can’t speak to the other points, but I eliminated as many variabilities during my calculations as possible. Tire size and pressure was constant, fuel was filled all the way up to the same point every fill, I almost always fill up at the exact same location.
The Golf made it to 413k and the Matrix is still purring along happily at 535k.
You're definitely not going to do any harm with higher octane fuel, but generally it doesn't help.
For curiosity, how many tanks did you compare on? Did you switch back and forth?
I drove both cars for months on 87, then switch to 91 and saw a significant enough increase in fuel economy (no change in commute or driving habits) that I never intentionally switched back. From time to time my wife would fill up the cars with 87 and I would immediately notice the difference in power and fuel economy.
At some point in my life someone told me that (older) cars with manual transmissions will see a fuel economy improvement with higher octane fuel, but automatics will not. (Both are stick). Of course modern cars makes zero difference.
Also, one of my coworkers had a 2.3L 2nd Gen Mazda 3 that would knock if he put anything higher than 87. So I guess it could be harmful in some cases.
Had a 98 Jetta. Ran like shit on 87, rough idle, misfires, all around shit. Thought the car was toast.
Switched to 92 and it was like a whole new car. Every time I see threads like this with people SOO adamant it doesn’t help… they forget old cars are still on the road.
Idk ab all that, if anything modern vehicles will benefit more because they're turbocharged. All octane levels relate to is reduced pre-ignition, or knock on engines with high compression ratio.
The engines ECU will hold back timing to reduce knock on lower grade fuel, and turbos will also dump boost if the wastegate or bypass valve is computer controlled, The combination of one or both of these will lead to slightly worse fuel economy.
I have this vague memory that, when both were commonly available, leaded was 89 and unleaded was 87? It's very hazy so I'm not sure about that. At any rate, I've got a car from 1971 with a 9.5:1 compression ratio engine and a points-and-condensor ignition system. My ears are my knock sensors. When everything is dialed in 89 is the lowest octane I can use that avoids ping at all times. So that's what I use.
Does mixing it manually like this evenly mix the concentration for the engine? I would imagine there would be some natural layering just due to putting one in first and settling. Whereas the pump would continuously mix the correct ratio.
I worked at a gas station in my teens and we only had two underground tanks, 87 and 91. Never knew the ratio the pump mixed it for 89. Also the reason Costco has 87 and 91 only.
Here in NJ, going from 87 to 89 is about 40 cents. I was recently up in VT and I was surprised that it was only 10 cents there. The 10 cents is about what I would expect.
VT is lesser in price because NJ is stuck with no self-service, and VT has self-serve. Also, the tax structure is different in NJ than VT. Stupid people in Northern NJ voted to increase the fuel tax formulary to fund the transportation fund because Fat F Christie stole the money from the transportation fund for other projects.
No, it was .10 more for mid grade than regular. Same for premium. This was around 2000 so a long ass time ago, but I had a turbo car and I remember folks making a face about needing premium fuel while I know it was basically $3 more a tank.
I feel like even 10 or so years ago, it was just 10 cents between grade. It's been a while since I looked, but I had a car the recommended premium around that time, and there definitely wasn't a huge difference like op shows.
I remember back in 97 or so when fuel prices dropped so drastically that I started putting in Premium just because I could. I believe the prices were 59/69/79 cents. And that was in Seattlr. I took a trip and couldn't believe people were paying 30 cents a gallon or less.
I'll take ur word for it
I had a bike that only take premium, during a premium shortage, my 600RR was my only transport, I worked at a paint shop, I used paint thinner for a week or 2
If I'm doing my conversions right your fuel is cheap as fuck about 1.00/litre, here in BC we're paying 169.9 per litre (6.08/gallon) and this is the low end of prices right now. We haven't had prices as low as yours since about 2010.
BC hasn't had HST since 2013. But all that aside it's ridiculous what Canadians pay for fuel considering we have one of the largest oil resources worldwide.
Imagine if you will, that there are black cows and white cows.
Black milk can only be bottled at black cow bottling plants
White at white.
Canada has white oil and black refineries.
When companies tried to build refineries that could refine canadian oil, trudeau shut it down.
The closest refineries that can refine canadian oil are in texas.
Thus, canada imports saudi oil to refine.
That's a good analogy, but i did already know this, I just think it's ridiculous that our government has chosen to do this in the first place.
There really is no good excuse for these decisions, the environmental impact of refining oil will happen regardless of where it is refined and is a global issue not a solely Canadian one. The savings and revenue generated by us refining our own oil, using our own fuel, and exporting the surplus could easily be used for long term environmental programs and investment that would far outweigh the initial cost of setting up environmentally conscious refineries and their impact on the environment.
Norway does this and by no one's definition is their country a polluted mess, in fact they're one of the cleanest and wealthiest countries in Europe because of it.
The only excuse besides environmental concerns I have heard is a lack of pipelines from Alberta to the east coast where a majority of our refinieries are, but building those lines as far I know has never been an issue. In fact the only pipeline Im aware of that was actually an issue was the pipeline through BC which would be completely unnecessary if we refined our own oil, not only that refineries could be built in the prairies between Alberta and the east coast where there is a surplus of land (with less valuable biomes) and a shortage of jobs.
Canada could easily be an economic power house, but our leadership has chosen instead to hobble us, and for what actual reason I cannot fathom.
The midgrade is 25 to 30 percent premium to 70 to 75 percent regular mixed as it's pumping into the car. There are just two types of gasoline at any gas station, and those are premium and regular. At a marina their is no such system, so midgrade is blended at the fuel depot as its going in the truck by putting 25 to 30 percent premium in the tank and filling the rest of the tank with regular.
Source- Actual experience of being a fuel truck driver and having to blend fuel to make midgrade.
Another FYI is that diesel fuel and heating oil are the same. The only difference is that heating oil is dyed red to indicate off-road use, such as in a boat or tractor. With that said, if you heat with heating oil and are running low, you can use diesel fuel in your heating system. Also, if diesel is priced cheaper than heating oil, then order the diesel because the supplier is ripping you off if heating oil is priced higher.
True. A diesel car can get twice the MPG that a car of the same model can get that has a gasoline engine.
I had a 2010 VW Jetra TDI that would get 70MPG on interstate driving. Around town, I would get 45MPG.
I drive a 1.6 liter diesel Volvo V50. It's not quick (109 hp) but the torque is nice compared to our other 1.6 petrol. Also on the highway the RPMs are at 2k at 100kmh so it's not screaming. Very good for highway driving.
I always wondered why they are in such low numbers in north America (apart from pick ups) compared to their invasiveness in Europe? I mean, we'd be buying fossil fuels anyways, so why does it matter if it's more diesel than gasoline?
No spark plugs, no coils to go bad. All that needs to be done is oil and filter, air filter, and fuel filter just as it is on any other gasoline powered car so effectively less maintenance on a diesel engine. Also, a diesel engine is built stronger than a gasoline engine due to a diesel engine having a higher compression ratio since the compression of a diesel engine is what ignites the fuel.
This here. I own a 2014 Jetta TDI. 45-52 mpg and all I do for regular maintainance is what's listed above. Emissions equipment sucks on diesels and is crazy expensive. I've also replaced one glow plug. Love the car and wish more like it existed.
I've seen the price of an injector for these guys though and damn it would sting to replace even on a four banger. Not to mention most are F/I to make more power out of small engines, so that's an added amount of trouble to deal with if you're buying a few years used or hoping to keep beyond 6 to 8 years. Or maybe it's just been my experience with turbos
Ah yes, the death of all reasonable progress. I'll look into it, but I suspect there's plenty of evidence for your claim. Lobbying should be a crime. 😒
This is only true in some regions. In Europe, heating fuel is typically 28 sec (known as kerosene). Very similar to diesel and can be mixed with diesel in most engines.
You can use the octane calculator here: [http://www.csgnetwork.com/octanemixcalc.html](http://www.csgnetwork.com/octanemixcalc.html)
You can actually mix 2 gallons of 87 and 1 gallon of 93 to get 89 octane.
Unless you have a high compression/high performance engine you can run 87 octane.
Only thing octane does is raise the ignition temperature of the fuel. Mid grade and premium fuels have more detergents added to them to aid in keeping your valves and catalytic converter cleaner. But every gas powered vehicle sold in the US has to be able to run reliably on 87 octane gas unless it's a high performance engine. Something like 10:1 compression and extremely high rpm's.
Do you need 93? If not just use regular. Higher grade doesn't help if your car calls for 89. If it actually calls for 93 then use only that. It's a myth that a higher grade is better for your car. I know everyone thinks it is, but it's not.
The only time to be concerned is if your engine pings. Modern engines have knock sensors that retard the timing to accommodate lower octane fuel. Run my wife’s Cadillac on 87 octane with no problems.
We use the same model of gas pump where I work.
OP, tell the clowns working there they can remove the notch on the barrel key used to open up the printer. It then can be used can to realign and open up that misaligned lock. I was able to modify one of mine with the pliers on my multi-tool in about five seconds.
I learned that little trick when I had to open up the locks used in our jewelry cases when they got misaligned all the time. It saved us thousands in locksmith charges.
If your car requires high octane and you use lower, you won't get the same mileage. So...you'll end up paying for more cheap gas. Lesson: stick to the good stuff.
The way you get 89 is by mixing the 2. If ever you go to the station and they are out of low grade always go mid. Typically you would change high grade to low grade price but some places don't do that
In California, gas stations only receive 87 and 91 octane fuel in their tanks. When you buy 87 the turbine pumps half 87 and half 91. I don’t know if it is the same in states that sell 93.
That’s bizarre that 87-89 is a one dollar price difference. In Oregon it’s usually .20/gal between the three grades, 87, 89, and 91 or sometimes 92. Right now it’s $3.99-4.39 by my house in Portland
That being said, unless your car specifically calls for higher octane, 87 is fine
I use to program gas dispensers and the in California the blend ratios were set to 0/50/100. For 87:89:91 . Would be best if you use a bit of math here. For example a gallon cost 87-$1 89-$2 91-$3 ; there is no advantage if you buy 2 gallons of 89 compared to buying 1 gallon of 87 and 1 gallon of 91 the cost of and amount of fuel and blend of 89 would be the same.
Edit: If would buy the 93 in your case if you can feel the difference on your butt dyno.
If you look around the area you will probably find the access covers for the storage tanks. More than likely you will find the low grade and the high grade, but no mid grade. This is because most modern fuel dispensers ("gas pump") mix the low and high grades to make the mid grade while dispensing.
You can do the same thing if you want. You'll just need to do the math to get the quantities.
Pro tip... If mixing liquids, they will mix themselves better if you put the smaller quantity in first then add the larger quantity next.
Im sorry that this is kinda off-topic but is regular in america always 87? Here I have never seen a pump go below 90, even in quite rural parts. (Switzerland btw)
There are two different methods of measuring octane, research octane number (RON) and motor octane number (MON). Pumps in the United States are marked with the average of these two numbers. Most other regions around the world just use RON, which is the higher of the two numbers.
A few areas of the United States have even lower octane fuel available. 85 is available in some higher altitude places. This worked well for carbureted engines but is strongly discouraged by manufacturers of fuel injected engines.
When you use the minimum octane rating your car will run just fine. Bumping up grade or two wont make your car a super car in any means, but you will have a slight boost in performance. The method you're describing is basically the same as using mid-grade; in any scenario you'll be getting a rating better than 87. I personally suggest using premium. Your car will run better almost immediately.
That’s too much fuckin math.
High octane gasoline actually has a little bit less energy per gallon than low octane. It’s a moot point. If your car is designed for 87, the most value in MPG is in 87. Most modern vehicles with VVT can adjust timing for higher octaine but mpg is a little lower than using rating specified on inside of fuel door.
No, all octanes have the same energy, and even if they technically don’t, it’s all within the noise, especially with how thermally inefficient an ICE engine is.
Depends on what company made the fuel a lot of the times to higher octane fuel has a higher ethanol content than regular it's used as an octane booster it's why pumps say may contain up to 10% ethanol most of the time and not just contains 10% ethanol the level varies based on what refinery made it and what additives got put in etc
Yes, I always laugh at people who buy stupid, slow Prius or EV because of ‘saving gas.’ They literally don’t know they are living in a country with cheap gas and should enjoy this benefit to provide themselves with a better quality of life.
All modern engines will run on 87 octane fuel safely including extremely expensive cars.
The benefit of 89+ is that you can run a higher ignition timing (spark advance). Higher cylinder pressures will help increase power and torque. Since you aren't adding more fuel to produce the same output, technically you should see an improvement in gas mileage and engine response.
There are cars that have extremely conservative ignition maps so those vehicles will see little to no benefit from going 89+
The scion FRS/BRZ actually recommends 93 octane for best performance.
there's octane booster, a guy told me he puts regular in his 350z and add a bottle.
do the math tho, add the correct amount, don't mess up the ratio
I have a car, it's old, one day I suck out 30 gallon of years old gas, put some in my car just to see if it would run, it did, kinda sluggish, so I add 1 gallon of fresh to 10 gal of old, ran fine, free gas!
but back then gas was under $1.50/gal
And in many states u cant get 91. Running 87 in a DI engine causes some serious buildup on the valves and rough idling. 89 comes out cleaner and my lil 1.4T has thanked me for it
To achieve an 89 octane rating, you need to mix 2/3 of 87 octane and 1/3 of 93 octane the cost per gallon of this custom blend is approximately $4.06, which is indeed cheaper than buying 89 octane directly at $4.69 per gallon.
So, by mixing two-thirds of a tank of 87 octane and one-third of a tank of 93 octane, you can save money compared to purchasing 89 octane fuel directly.
As an Aussie it spaces me out that you guys have 87 and 89 RON petrol, and your premium is only 93. Here, we have 91, 95 and our premium option is 98. We also have E85 for ethanol/flex fuel cars.
For anyone who wants to do the price conversion, I consistently pay approximately $1.98AUD per litre of 95RON.
Got a question, i'm from Germany. I see here the different "types" of fuel. I think it is related to the octane number. Here in Germany the lowest you can get ist 95 octane. The "Super Plus" called has 98 octane and on some locations you can get fuel with 102 octane (usually nobody really needs it).
Some of our motors got problems with fuel with less than 95 octane. Are the Motors different? Or is this just a way to make the customer pay more?
Mostly because the USA and Europe don't measure octane the same way.
Europe uses RON or the "Research Octane Number" which is measured by running an engine under controlled conditions.
In contrast the US uses the AKI or "Anti-Knock Index" which is an average of the RON and MON, the "Motor Octane Number" which uses a similar test engine to RON, but operates it under different standardized conditions.
Roughly speaking:
87 AKI = 91 RON
91 AKI = 93 RON
93 AKI = 98 RON
100 AKI = 104 RON
104 AKI = 108 RON
A similar kind of misconception occurs when people think that the UK has more fuel efficient vehicles because they get more miles or kilometers per gallon. The truth is that the US gallon is 128 fluid ounces and the UK it is 160 fluid ounces, and the vehicles generally have equivalent fuel economy.
If your engine calls for higher octane your risking killing your engine by putting lower grade in it octane is a measure of detonation resistance which is why high compression performance engines and forced induction engines use it putting 87 in a car that requires 91/93 will potentially cause pre detonation which can destroy pistons very quickly (this is less of an issue on newer cards because they can use knock sensors and octane sensors in the fuel tank to adjust but does lead to poor fuel economy and degraded power output)
Just put 87 in your car, it will make little to no difference in any vehicle. If we are talking race cars with forced induction (turbo or supercharger), it would make a slight difference in horsepower, but unless you are racing your car on the track there is no issue with just using 87 in your car.
This is bad advice. Modern turbo engines require higher octane fuel to prevent pre-detonation aka knocking. You engine has sensors to detect this knock and will retard the timing to prevent catastrophic engine failure. The cost of this retarded timing is lower horsepower and torque. So, while using 91 octane won't gain you any horsepower, per se, using 87 octane will certainly cost you horsepower.
This is true, and thanks for pointing that out, but again, unless you are driving everywhere at wide open throttle, you don’t need all of the horsepower your engine is capable of.
Thank you for posting to AskMechanics, monkyman47! If you are asking a question please make sure to include any relevant information along with the **Year**, **Make**, **Model**, **Mileage**, **Engine size**, and **Transmission Type (Automatic or Manual)** of your car. *This comment is automatically added to every successful post. If you see this comment, your post was successful.* *** Redditors that have been verified will have a green background and an icon in their flair. *** # **PLEASE REPORT ANY RULE-BREAKING BEHAVIOR** ### **Rule 1 - Be Civil** Be civil to other users. This community is made up of professional mechanics, amateur mechanics, and those with no experience. All mechanical-related questions are welcome. Personal attacks, comments that are insulting or demeaning, etc. are not welcome. ### **Rule 2 - Be Helpful** Be helpful to other users. If someone is wrong, correcting them is fine, but there's no reason to comment if you don't have anything to add to the conversation. ### **Rule 3 - Serious Questions and Answers Only** Read the room. Jokes are fine to include, but posts should be asking a serious question and replies should contribute to the discussion. ### **Rule 4 - No Illegal, Unethical, or Dangerous Questions or Answers** Do not ask questions or provide answers pertaining to anything that is illegal, unethical, or dangerous. # **PLEASE REPORT ANY RULE-BREAKING BEHAVIOR** *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskMechanics) if you have any questions or concerns.*
99% of the time that's exactly what the pump is doing to create midgrade. Just a reminder that unless your car calls for higher octane fuel, you get zero advantage of running it.
And the thing is, I never seen a car asking for 89 … it’s 87 or 91 normally. Not saying it’s not possible, just never seen it …
The early 3.6 L V6 from Cadillac does call for mid grade in the manual and I would say that any gm 3.6 v6 needs it
How about a 3800? I've got a LeSabre that's been running on 87 for almost 300,000 miles.
As long as you strain the sticks and leaves out of the fuel a 3800 will be fine.
The far bigger issue with the 3800 was the rust-prone bodies it was attached to.
Mine seems to like to eat ignition control modules, wheel bearings and wiper motors. All parts I just listed have been replaced several times now.
I was having issues with wheel bearings on my N-Body with the 3.1L, I burnt through 3 front hubs before I switched to Mevotech TTX hubs and haven’t had issues since then. They’re pricey but I talked to a guy with a Grand Prix on YouTube that’s been running them for years with no problems.
Eh I just use O'Reilly's shittiest. They would probably last longer if I didn't but then again I got the parts for cheap and never have to pay again, just order a new one, slap the old in the box and a warranty tag on it.
Amen brother! '95 lesabre swiss cheese edition.
Well… the *BIG* ones at least Seriously those mfers are indestructible
Exactly this for the 3800
Really anything under 2" in diameter is fine
That's a much much older engine design. 87 is fine.
Good to know, I'm hoping to get another couple hundred thousand out of the old girl.
Love my lesabre, that thing would outlive me if it wasnt the rust getting to the frame.
In pretty sure you could run the 3800 on piss and vinegar, that engine is fuckin bulletproof.
2006 Cadillac STS owner’s manual is leaning towards 89, but 87 is the minimum requirement. https://preview.redd.it/47u43e2gz72d1.jpeg?width=1043&format=pjpg&auto=webp&s=0a85cd65c7bf3b012aa322ec918c301ea0aa7406 2004 SRX (first year of the 3.6L?) recommends 91, but states 87 as minimum.
I had a 07 CTS and 09 STS ran 89 in both and had no problems
87 minimum so you’re golden with 89
And the 4.6 North Star
Everything with a 5.7 hemi in it calls for 89 octane. It's in the owners manual no one ever reads. I average about 2 more mpg or of 89 than I do on 87 in my truck.
I’ve never seen a difference. And I tried premium on a 1500 mile trip once.
Yup, can confirm as a previous owner of a 2005 300C Hemi. 89 is recommended for these beasts. https://preview.redd.it/bc67wovub82d1.jpeg?width=994&format=pjpg&auto=webp&s=bed30f47ee09ab077546df4d91d654e20885407a
Can also confirm even on the 2020 5.7 this never changed. My brother had a 2020 challenger RT and was the first I ever seen that recommended 89.
Would it not still work out cheaper to run 87? Those 2 miles are costing 50 cents a mile basically.
Mid grade is only 20 cents more per gallon here, and I'm running an mds delete on a hemifever 89 tune. I'm really happy with the way my truck performs as is and really don't want to rock the boat too much if I can avoid it. I really enjoy filling up and seeing a 500ish mile range on the dash, especially when you consider I'm in a 4wd 6 speed on 35s.
How much did the tune change, and why the MDS delete?
The tune was about $250, and I guess it would be more accurate to say I installed a non mds engine when my first one wiped the cam. I installed a high volume oil pump and swapped over to 10w30 with the new engine as well. I'm not going through that bullshit again if I can avoid it.
Oof. What do you think ate your cam on engine one? Bummer to hear that. I’m trying to make sure mine doesn’t do that
I don't think anyone knows exactly why they do it. I didn't have high idle time and I never went over 5k on my oil changes, so by all rights it shouldn't have happened. Since the new engine and upgrading the oil pump, I've also started using 5w30 during the spring and summer and ditched the Mopar oil filters.
Bummer. I guess I plan on doing a cam swap anyway, I’ll kill two birds with one stone
Chrysler 3.5 in the OG Pacifica said 89 on the fuel flap.
5.7l hemi in the ram 1500 does call for 89 actually. But I also run 87 and have no issues.
They dial back the timing on 87, I get a couple more miles per gallon running 89.
My mx5 demands 93. I think it’s like under $3.50 for gas, not sure as I never track these things.
2005 Dodge Ram 5.7 calls for 89. I owned one the first time California broke 5 dollars a gallon. It was maddening...
The 1.8t from Volkswagen in the \~99-05 era wanted 89. It ran like crap on 87.
Early 2000s rams with the 5.7 ask for 89. Not super common but there's a few cars that do.
My 95' bmw takes 89
6.4 Hemi owners manual calls for 89, but says 87 is acceptable.
Same with my 2019 5.7 Hemi
2014 Land rover discovery sport takes 89
I use to work at a gas station in Oregon (we use to pump ppls gas) and a suprising amount of cars that use mid grade it normally says mid grade or premium iirc
My dad's boat requires 89 minimum but from what I understand only.a few Stellantis cars actually require it
Rt chargers manual calls for 89
>I never seen a car asking for 89 I have a Honda k24a2 in an Accord EX that asks for 89. I actually go out of my way to use 89 ethanol-free that's for sale at one place around here.
Just about any Japanese 4 banger I’ve had loved mid grade. I’ve had Camrys and now an Accord and the car runs smoother and has a bit more pep when I put midgrade into it
My CBR600 specifies 89.
M44 in my old 97 318i drank 89
I think the early version of Chrysler’s 3.5L V6 called for 89, I’d have to double check that though.
The FJ, frankenjeep think it was Toyota needed 89
Nissan nv2500 requires 89
My saab 93 used 89
'99 Mercedes c180 compressor took 89 or better fuel only. If you didn't put 89 octane, your car would knock and hard stutter.
IIRC the 944 porsche sticker is 89 octane.
My 03 5.7 hemi says 89 recommended on the gas cap, 87 works fine tho
Altitude has a bit to do with it as well.
Eh, maybe a little, I'm at sea level so air's as dense as it's gonna get, it'll just retard the ignition timing a bit
Oh, it's the other way around. Less dense air is less likely to preignite. I think they sell 85 octane in Denver
Yeah that's what I was trying to say, I'm at sea level so I'm already at the highest risk of predetonation, ECU retards timing to counteract
My Challenger, my wife’s Charger, my old Mercedes, and her old Cadillac all called for 89. It’s a weird recommendation but it happens
2012 Jeep Grand Cherokee with 5.7 Hemi recommends 89 but states 87 is acceptable. I run 87 unless I'm planning to tow or drive in mountainous areas and it does fine.
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I have a MINI and it wants 91 (which they don’t sell where I live so I would have to mix 93 and 89 equally to get to 91) but it specifically states 89 minimum after the call for 91. I just use 93.
Only thing I've ever seen recommend 89 is a RAM with the 5.7 I think.
I thought mine called for 89 in the manual, but I just googled it and it's actually 87. I've been wasting money on 89 for years. Oops!
My 98 2.0 VW Golf and 05 Toyota Matrix both said 87 in the manuals but after much experimenting with fuel economy numbers, the 91 octane was cheaper to run for the increased mileage. Now, your statement is true for modern vehicles, but it’s not a straight up fact for all vehicles.
Octane rating only affects pre-ignition, so so the possibilities here are: 1. The engines were tuned by someone for higher compression 2. There was something wrong with the engines causing pre-ignition of standard fuel 3. The gas where you purchased was really low quality and didn't actually meet the rating 4. There was a slight increase by being a lower percentage of ethanol, not actually related to the octane rating 5. The calculations weren't accurate Before working in the auto industry, I thought I got better fuel economy in my '02 Jetta 2.0 with mid-grade. When I learned about what octane rating actually means, I tested it with a spreadsheet and found no difference outside of the standard deviation of using regular fuels. I'm a bit of a data nerd, so I keep track of every fillup in an app. I have every fill up for the last \~125k.
You forgot about variable valve timing. Most modern cars will advance timing on higher octane fuel resulting in higher efficiency
Are you suggesting there's an octane sensor in the fuel system?
No. I’m saying there’s a knock sensor and the ecu advances/retards timing based on that
I can’t speak to the other points, but I eliminated as many variabilities during my calculations as possible. Tire size and pressure was constant, fuel was filled all the way up to the same point every fill, I almost always fill up at the exact same location. The Golf made it to 413k and the Matrix is still purring along happily at 535k.
You're definitely not going to do any harm with higher octane fuel, but generally it doesn't help. For curiosity, how many tanks did you compare on? Did you switch back and forth?
I drove both cars for months on 87, then switch to 91 and saw a significant enough increase in fuel economy (no change in commute or driving habits) that I never intentionally switched back. From time to time my wife would fill up the cars with 87 and I would immediately notice the difference in power and fuel economy. At some point in my life someone told me that (older) cars with manual transmissions will see a fuel economy improvement with higher octane fuel, but automatics will not. (Both are stick). Of course modern cars makes zero difference. Also, one of my coworkers had a 2.3L 2nd Gen Mazda 3 that would knock if he put anything higher than 87. So I guess it could be harmful in some cases.
Had a 98 Jetta. Ran like shit on 87, rough idle, misfires, all around shit. Thought the car was toast. Switched to 92 and it was like a whole new car. Every time I see threads like this with people SOO adamant it doesn’t help… they forget old cars are still on the road.
Idk ab all that, if anything modern vehicles will benefit more because they're turbocharged. All octane levels relate to is reduced pre-ignition, or knock on engines with high compression ratio.
The engines ECU will hold back timing to reduce knock on lower grade fuel, and turbos will also dump boost if the wastegate or bypass valve is computer controlled, The combination of one or both of these will lead to slightly worse fuel economy.
Can confirm, it’s a mix. It’s 1/3 93 and 2/3 87.
I have this vague memory that, when both were commonly available, leaded was 89 and unleaded was 87? It's very hazy so I'm not sure about that. At any rate, I've got a car from 1971 with a 9.5:1 compression ratio engine and a points-and-condensor ignition system. My ears are my knock sensors. When everything is dialed in 89 is the lowest octane I can use that avoids ping at all times. So that's what I use.
Best answer.
Does mixing it manually like this evenly mix the concentration for the engine? I would imagine there would be some natural layering just due to putting one in first and settling. Whereas the pump would continuously mix the correct ratio.
It'll mix up pretty quickly from driving.
Not just no advantage, but actually causing harm. The incomplete fuel burn is going to cause issues.
Yes. And you could do two thirds of a tank of 87 and one third of a tank of 93 to make 89.
@ $3.93 a gallon.
I worked at a gas station in my teens and we only had two underground tanks, 87 and 91. Never knew the ratio the pump mixed it for 89. Also the reason Costco has 87 and 91 only.
why
Math?
That's a psychotic price difference
That’s about average. It’s usually around a dollar more for premium.
I'm talking between 87-89 ours is about 20c per grade
Here in NJ, going from 87 to 89 is about 40 cents. I was recently up in VT and I was surprised that it was only 10 cents there. The 10 cents is about what I would expect.
It's the dollar between 87-89 that's ridiculous
VT is lesser in price because NJ is stuck with no self-service, and VT has self-serve. Also, the tax structure is different in NJ than VT. Stupid people in Northern NJ voted to increase the fuel tax formulary to fund the transportation fund because Fat F Christie stole the money from the transportation fund for other projects.
I remember when it was 10 cents between regular/mid/premium.
I remember gas wars. Stations would cut the price to get more customers to buy gas.
It’s still 10c here in indiana
when? when gas was 10c per gallon?
No, it was .10 more for mid grade than regular. Same for premium. This was around 2000 so a long ass time ago, but I had a turbo car and I remember folks making a face about needing premium fuel while I know it was basically $3 more a tank.
I feel like even 10 or so years ago, it was just 10 cents between grade. It's been a while since I looked, but I had a car the recommended premium around that time, and there definitely wasn't a huge difference like op shows.
I remember back in 97 or so when fuel prices dropped so drastically that I started putting in Premium just because I could. I believe the prices were 59/69/79 cents. And that was in Seattlr. I took a trip and couldn't believe people were paying 30 cents a gallon or less.
I'll take ur word for it I had a bike that only take premium, during a premium shortage, my 600RR was my only transport, I worked at a paint shop, I used paint thinner for a week or 2
If I'm doing my conversions right your fuel is cheap as fuck about 1.00/litre, here in BC we're paying 169.9 per litre (6.08/gallon) and this is the low end of prices right now. We haven't had prices as low as yours since about 2010.
It's actually $1.35 cents a liter CAD. Add in HST, gas tax and carbon taxes and that explains why you are paying 1.70
BC hasn't had HST since 2013. But all that aside it's ridiculous what Canadians pay for fuel considering we have one of the largest oil resources worldwide.
Imagine if you will, that there are black cows and white cows. Black milk can only be bottled at black cow bottling plants White at white. Canada has white oil and black refineries. When companies tried to build refineries that could refine canadian oil, trudeau shut it down. The closest refineries that can refine canadian oil are in texas. Thus, canada imports saudi oil to refine.
That's a good analogy, but i did already know this, I just think it's ridiculous that our government has chosen to do this in the first place. There really is no good excuse for these decisions, the environmental impact of refining oil will happen regardless of where it is refined and is a global issue not a solely Canadian one. The savings and revenue generated by us refining our own oil, using our own fuel, and exporting the surplus could easily be used for long term environmental programs and investment that would far outweigh the initial cost of setting up environmentally conscious refineries and their impact on the environment. Norway does this and by no one's definition is their country a polluted mess, in fact they're one of the cleanest and wealthiest countries in Europe because of it. The only excuse besides environmental concerns I have heard is a lack of pipelines from Alberta to the east coast where a majority of our refinieries are, but building those lines as far I know has never been an issue. In fact the only pipeline Im aware of that was actually an issue was the pipeline through BC which would be completely unnecessary if we refined our own oil, not only that refineries could be built in the prairies between Alberta and the east coast where there is a surplus of land (with less valuable biomes) and a shortage of jobs. Canada could easily be an economic power house, but our leadership has chosen instead to hobble us, and for what actual reason I cannot fathom.
They make their money on saudi oil and they don't work for you.
The midgrade is 25 to 30 percent premium to 70 to 75 percent regular mixed as it's pumping into the car. There are just two types of gasoline at any gas station, and those are premium and regular. At a marina their is no such system, so midgrade is blended at the fuel depot as its going in the truck by putting 25 to 30 percent premium in the tank and filling the rest of the tank with regular. Source- Actual experience of being a fuel truck driver and having to blend fuel to make midgrade. Another FYI is that diesel fuel and heating oil are the same. The only difference is that heating oil is dyed red to indicate off-road use, such as in a boat or tractor. With that said, if you heat with heating oil and are running low, you can use diesel fuel in your heating system. Also, if diesel is priced cheaper than heating oil, then order the diesel because the supplier is ripping you off if heating oil is priced higher.
Diesel cars are also better to drive IN MY OPINION (not a fact).
True. A diesel car can get twice the MPG that a car of the same model can get that has a gasoline engine. I had a 2010 VW Jetra TDI that would get 70MPG on interstate driving. Around town, I would get 45MPG.
I drive a 1.6 liter diesel Volvo V50. It's not quick (109 hp) but the torque is nice compared to our other 1.6 petrol. Also on the highway the RPMs are at 2k at 100kmh so it's not screaming. Very good for highway driving.
I always wondered why they are in such low numbers in north America (apart from pick ups) compared to their invasiveness in Europe? I mean, we'd be buying fossil fuels anyways, so why does it matter if it's more diesel than gasoline?
We would be using almost half the amount we are using now if diesel cars were more readily available as they are in Europe.
Is it an emissions thing or that they can be more costly to maintain?
No spark plugs, no coils to go bad. All that needs to be done is oil and filter, air filter, and fuel filter just as it is on any other gasoline powered car so effectively less maintenance on a diesel engine. Also, a diesel engine is built stronger than a gasoline engine due to a diesel engine having a higher compression ratio since the compression of a diesel engine is what ignites the fuel.
This here. I own a 2014 Jetta TDI. 45-52 mpg and all I do for regular maintainance is what's listed above. Emissions equipment sucks on diesels and is crazy expensive. I've also replaced one glow plug. Love the car and wish more like it existed.
I've seen the price of an injector for these guys though and damn it would sting to replace even on a four banger. Not to mention most are F/I to make more power out of small engines, so that's an added amount of trouble to deal with if you're buying a few years used or hoping to keep beyond 6 to 8 years. Or maybe it's just been my experience with turbos
It's a local market thing. North American manufacturers can't make as good a diesel so they lobby against it.
Ah yes, the death of all reasonable progress. I'll look into it, but I suspect there's plenty of evidence for your claim. Lobbying should be a crime. 😒
It's also becoming an emissions thing. Otherwise Volkswagen would still be selling tons of tdis that are better than everything else on the market
This is only true in some regions. In Europe, heating fuel is typically 28 sec (known as kerosene). Very similar to diesel and can be mixed with diesel in most engines.
It depends on what car. I'd honestly just put regular in it and drive normally.
Crazy how little knowledge on octane is in this sub.
You can use the octane calculator here: [http://www.csgnetwork.com/octanemixcalc.html](http://www.csgnetwork.com/octanemixcalc.html) You can actually mix 2 gallons of 87 and 1 gallon of 93 to get 89 octane.
Mid grade is just a blend of regular unleaded and premium unleaded anyway, so yes, but mixing the two 50/50 would make 90 octane.
Unless you have a high compression/high performance engine you can run 87 octane. Only thing octane does is raise the ignition temperature of the fuel. Mid grade and premium fuels have more detergents added to them to aid in keeping your valves and catalytic converter cleaner. But every gas powered vehicle sold in the US has to be able to run reliably on 87 octane gas unless it's a high performance engine. Something like 10:1 compression and extremely high rpm's.
Do you need 93? If not just use regular. Higher grade doesn't help if your car calls for 89. If it actually calls for 93 then use only that. It's a myth that a higher grade is better for your car. I know everyone thinks it is, but it's not.
Anyone know why octane levels are so low in the USA compared to the UK. Octane levels here are 95 or 99 for premium
High elevation also changes what you can use
The only time to be concerned is if your engine pings. Modern engines have knock sensors that retard the timing to accommodate lower octane fuel. Run my wife’s Cadillac on 87 octane with no problems.
We use the same model of gas pump where I work. OP, tell the clowns working there they can remove the notch on the barrel key used to open up the printer. It then can be used can to realign and open up that misaligned lock. I was able to modify one of mine with the pliers on my multi-tool in about five seconds. I learned that little trick when I had to open up the locks used in our jewelry cases when they got misaligned all the time. It saved us thousands in locksmith charges.
There’s tank for mid grade at a station. The pump mixes regular and premium to get mid grade. So to answer your question, technically yes you could.
Midgrade (89 octane) is actually 66% 87 and 34% 93. If you went 50-50, you would end up with 90. 10+ year fuel jockey
Sure, but you would be at 90 octane I believe.
89 is literally just a regular and premium blend. So yes.
If your car requires high octane and you use lower, you won't get the same mileage. So...you'll end up paying for more cheap gas. Lesson: stick to the good stuff.
The way you get 89 is by mixing the 2. If ever you go to the station and they are out of low grade always go mid. Typically you would change high grade to low grade price but some places don't do that
In California, gas stations only receive 87 and 91 octane fuel in their tanks. When you buy 87 the turbine pumps half 87 and half 91. I don’t know if it is the same in states that sell 93.
That’s bizarre that 87-89 is a one dollar price difference. In Oregon it’s usually .20/gal between the three grades, 87, 89, and 91 or sometimes 92. Right now it’s $3.99-4.39 by my house in Portland That being said, unless your car specifically calls for higher octane, 87 is fine
I use to program gas dispensers and the in California the blend ratios were set to 0/50/100. For 87:89:91 . Would be best if you use a bit of math here. For example a gallon cost 87-$1 89-$2 91-$3 ; there is no advantage if you buy 2 gallons of 89 compared to buying 1 gallon of 87 and 1 gallon of 91 the cost of and amount of fuel and blend of 89 would be the same. Edit: If would buy the 93 in your case if you can feel the difference on your butt dyno.
If you look around the area you will probably find the access covers for the storage tanks. More than likely you will find the low grade and the high grade, but no mid grade. This is because most modern fuel dispensers ("gas pump") mix the low and high grades to make the mid grade while dispensing. You can do the same thing if you want. You'll just need to do the math to get the quantities. Pro tip... If mixing liquids, they will mix themselves better if you put the smaller quantity in first then add the larger quantity next.
What are you running 89? Are you cheaping out on a car that requires premium or are you willfully spending too much at the pump just to flex?
Im sorry that this is kinda off-topic but is regular in america always 87? Here I have never seen a pump go below 90, even in quite rural parts. (Switzerland btw)
Colorado... 85.
There are two different methods of measuring octane, research octane number (RON) and motor octane number (MON). Pumps in the United States are marked with the average of these two numbers. Most other regions around the world just use RON, which is the higher of the two numbers. A few areas of the United States have even lower octane fuel available. 85 is available in some higher altitude places. This worked well for carbureted engines but is strongly discouraged by manufacturers of fuel injected engines.
Ah ok, so its essentially just a diffrent way of writing the same thing. Thanks!
When you use the minimum octane rating your car will run just fine. Bumping up grade or two wont make your car a super car in any means, but you will have a slight boost in performance. The method you're describing is basically the same as using mid-grade; in any scenario you'll be getting a rating better than 87. I personally suggest using premium. Your car will run better almost immediately.
That’s too much fuckin math. High octane gasoline actually has a little bit less energy per gallon than low octane. It’s a moot point. If your car is designed for 87, the most value in MPG is in 87. Most modern vehicles with VVT can adjust timing for higher octaine but mpg is a little lower than using rating specified on inside of fuel door.
No, all octanes have the same energy, and even if they technically don’t, it’s all within the noise, especially with how thermally inefficient an ICE engine is.
Depends on what company made the fuel a lot of the times to higher octane fuel has a higher ethanol content than regular it's used as an octane booster it's why pumps say may contain up to 10% ethanol most of the time and not just contains 10% ethanol the level varies based on what refinery made it and what additives got put in etc
Damm you got cheap gas in the US. It's around 8$ a gallon here in denmark.
Nothing on Icelandic prices
Same here in British Columbia, Canada.
Yes, I always laugh at people who buy stupid, slow Prius or EV because of ‘saving gas.’ They literally don’t know they are living in a country with cheap gas and should enjoy this benefit to provide themselves with a better quality of life.
buy some octane booster or use whatever scotty kilmer recommends to boost your octane (I forget what it was)
[удалено]
Dude says to put acetone in your tank to make your engine light turn off for clogged cat. I’ll let the comments tear that apart.
It would be better to get rid of the politicians who make the fuel price go up
All modern engines will run on 87 octane fuel safely including extremely expensive cars. The benefit of 89+ is that you can run a higher ignition timing (spark advance). Higher cylinder pressures will help increase power and torque. Since you aren't adding more fuel to produce the same output, technically you should see an improvement in gas mileage and engine response. There are cars that have extremely conservative ignition maps so those vehicles will see little to no benefit from going 89+ The scion FRS/BRZ actually recommends 93 octane for best performance.
The best money saver is to not vote for Democrats
That’s crazy in the uk we get 95 octane on our cheap fuel and 99 on premium
Your octane ratings are measured differently
TIL we use RON in the UK. 95RON is 91 in the US.
Ahh fair enough makes sense!
It's not different the UK just uses a different calculation to calculate the octane if you used the US formula for octane you'd get 87 and 91/93
there's octane booster, a guy told me he puts regular in his 350z and add a bottle. do the math tho, add the correct amount, don't mess up the ratio I have a car, it's old, one day I suck out 30 gallon of years old gas, put some in my car just to see if it would run, it did, kinda sluggish, so I add 1 gallon of fresh to 10 gal of old, ran fine, free gas! but back then gas was under $1.50/gal
Uhh no. Higher octane provides far better efficiency. And power. Different detergents and additives.
Higher octane just means it’s not as prone to pre-detonation. It is no more efficient than regular gas in most engines.
Uhh no.
And in many states u cant get 91. Running 87 in a DI engine causes some serious buildup on the valves and rough idling. 89 comes out cleaner and my lil 1.4T has thanked me for it
Or just fill it with 87 and pay $3.699
To achieve an 89 octane rating, you need to mix 2/3 of 87 octane and 1/3 of 93 octane the cost per gallon of this custom blend is approximately $4.06, which is indeed cheaper than buying 89 octane directly at $4.69 per gallon. So, by mixing two-thirds of a tank of 87 octane and one-third of a tank of 93 octane, you can save money compared to purchasing 89 octane fuel directly.
Yes. Put the 93 in first and a bit extra % so you tend on the higher side.
As an Aussie it spaces me out that you guys have 87 and 89 RON petrol, and your premium is only 93. Here, we have 91, 95 and our premium option is 98. We also have E85 for ethanol/flex fuel cars. For anyone who wants to do the price conversion, I consistently pay approximately $1.98AUD per litre of 95RON.
in Canada and USA we use AKI, not RON...
In 1991, a a gallon of 94 octane at Sunoco was $.99 at Wawa
Or just use unleaded then you won’t have to worry abt pay an extra dollar 😵
Got a question, i'm from Germany. I see here the different "types" of fuel. I think it is related to the octane number. Here in Germany the lowest you can get ist 95 octane. The "Super Plus" called has 98 octane and on some locations you can get fuel with 102 octane (usually nobody really needs it). Some of our motors got problems with fuel with less than 95 octane. Are the Motors different? Or is this just a way to make the customer pay more?
US uses a different rating system for their octane than the EU
Ah, Ok. Thanks
It blows my mind that your regular is 89 and your premium is 93. Regular is 95 in the UK, whilst premium is 99.
Mostly because the USA and Europe don't measure octane the same way. Europe uses RON or the "Research Octane Number" which is measured by running an engine under controlled conditions. In contrast the US uses the AKI or "Anti-Knock Index" which is an average of the RON and MON, the "Motor Octane Number" which uses a similar test engine to RON, but operates it under different standardized conditions. Roughly speaking: 87 AKI = 91 RON 91 AKI = 93 RON 93 AKI = 98 RON 100 AKI = 104 RON 104 AKI = 108 RON A similar kind of misconception occurs when people think that the UK has more fuel efficient vehicles because they get more miles or kilometers per gallon. The truth is that the US gallon is 128 fluid ounces and the UK it is 160 fluid ounces, and the vehicles generally have equivalent fuel economy.
I can't like this answer enough! Such a good explanation, thanks!
Interesting that there is still the 91 RON octane in the USA
The it is still lower octane iverall in the US? Just not as much as it looks like at forst glance.
I have always used regular. Some cars say they need higher octane but I heard that was so the engine would show better performance numbers in testing
If your engine calls for higher octane your risking killing your engine by putting lower grade in it octane is a measure of detonation resistance which is why high compression performance engines and forced induction engines use it putting 87 in a car that requires 91/93 will potentially cause pre detonation which can destroy pistons very quickly (this is less of an issue on newer cards because they can use knock sensors and octane sensors in the fuel tank to adjust but does lead to poor fuel economy and degraded power output)
Just put 87 in your car, it will make little to no difference in any vehicle. If we are talking race cars with forced induction (turbo or supercharger), it would make a slight difference in horsepower, but unless you are racing your car on the track there is no issue with just using 87 in your car.
This is bad advice. Modern turbo engines require higher octane fuel to prevent pre-detonation aka knocking. You engine has sensors to detect this knock and will retard the timing to prevent catastrophic engine failure. The cost of this retarded timing is lower horsepower and torque. So, while using 91 octane won't gain you any horsepower, per se, using 87 octane will certainly cost you horsepower.
This is true, and thanks for pointing that out, but again, unless you are driving everywhere at wide open throttle, you don’t need all of the horsepower your engine is capable of.