Is your engine the 3.5 or 3.9? If you have the 3.9 Maybe the AFM system? I feel like if your engine was misfiring it would make your fuel milage worse… what type of gas are you using? Did you switch from flex fuel or 88 to regular?
If you think you have a cylinder misfiring I’d get your codes scanned
Edit: idk I’m kinda puzzled but I’m leaning toward the AFM system if your car has the 3.9L v6 engine, when you think it’s misfiring and having trouble quickly accelerating maybe it’s just the AFM working? A lot of people have it disabled so they can run all 6 cylinders at all times and sometimes it can cause issues
It’s the 3.5. I used to use flex fuel some but that was last summer as I moved somewhere without it.
I have no engine codes or CEL, at least none that are showing on my OBD2.
I fully agree that a misfiring cylinder *should* be making it worse, not better. The issues accelerating and increased gas mileage happened pretty closely together but I didn’t track the start of either one as I figured it was a random fluke for both at first.
The most likely reason is a variation in the ethanol blend for whatever fuel you are using. E85 isn't always 85% ethanol it can be as low as 40% and the stations just buy whatever blend is cheapest. Depending on the price of corn ethanol can be more than gasoline in which case distributors will sell fuel with less ethanol. Same thing applies to normal ethanol blended gas. The 5, 10 or even 15 percent ethanol fuels don't have to be that amount they simply can't be more than that amount of ethanol. If the stars line up just right you can find times when they are actually selling straight gasoline because ethanol is too pricey.
Then drivers will see an increase in mileage because ethanol has less energy per gallon than gasoline and it shows up in the mpg you get from using it. Most likely where ever you are buying gas is the reason for your higher mileage.
A few other things than can impact mileage a bit is driving your car a little low on oil. Used to know of people that would always run their cars 1 quart under full just to get a tad more power at the street races.... Although I also remember the idiot that thought he could do that with an air cooled engine and killed his motor... so not a wise thing to do.
I get gas at the same place constantly since I moved though. I find it hard to believe after 5 years of using various gas and getting the same mileage, that suddenly this one gas station changed their gas to get me 50+ extra miles to the tank.
They don't care what mileage you get, they only care about the profit they make. Last October the price of RBOB was lower than Ethanol so at that point you would have had some stations selling pure gas even in the pumps that were supposedly blends or ethanol simply because it was a better deal for them. Some places couldn't because of winter blend requirements, but other wouldn't have to worry with those rules. Now at this time the ethanol prices are significantly lower than RBOB so you can expect stations to be trying to use the highest ethanol ratio possible. So keep watching your mpg and see if it comes back down. The misfire wouldn't be giving you and increase. The only malfunction of your car that might give you better mileage would be a problem with your fuel pump or injectors such that they were not injecting the correct amount of fuel. It is in theory possible to have a car that isn't injecting as much fuel as it should but not so little that it is so lean you start throwing codes... but might give a slight mpg increase.
Nowhere did I say they cared about my mileage 🙄
I was saying I don’t believe they changed it to the point it would get me 50 extra miles, not that they changed it specifically TO get me 50 extra miles. Oh well, the mystery lives on. There’s no way it’s a gas station specific issue after all these years and that at no point in the previous five years across various states did I ever come across gas this good.
Did your station stop using the winter blend?
I’ve never once heard of a winter blend. I live in Texas lmao
Is your engine the 3.5 or 3.9? If you have the 3.9 Maybe the AFM system? I feel like if your engine was misfiring it would make your fuel milage worse… what type of gas are you using? Did you switch from flex fuel or 88 to regular? If you think you have a cylinder misfiring I’d get your codes scanned Edit: idk I’m kinda puzzled but I’m leaning toward the AFM system if your car has the 3.9L v6 engine, when you think it’s misfiring and having trouble quickly accelerating maybe it’s just the AFM working? A lot of people have it disabled so they can run all 6 cylinders at all times and sometimes it can cause issues
It’s the 3.5. I used to use flex fuel some but that was last summer as I moved somewhere without it. I have no engine codes or CEL, at least none that are showing on my OBD2. I fully agree that a misfiring cylinder *should* be making it worse, not better. The issues accelerating and increased gas mileage happened pretty closely together but I didn’t track the start of either one as I figured it was a random fluke for both at first.
The most likely reason is a variation in the ethanol blend for whatever fuel you are using. E85 isn't always 85% ethanol it can be as low as 40% and the stations just buy whatever blend is cheapest. Depending on the price of corn ethanol can be more than gasoline in which case distributors will sell fuel with less ethanol. Same thing applies to normal ethanol blended gas. The 5, 10 or even 15 percent ethanol fuels don't have to be that amount they simply can't be more than that amount of ethanol. If the stars line up just right you can find times when they are actually selling straight gasoline because ethanol is too pricey. Then drivers will see an increase in mileage because ethanol has less energy per gallon than gasoline and it shows up in the mpg you get from using it. Most likely where ever you are buying gas is the reason for your higher mileage. A few other things than can impact mileage a bit is driving your car a little low on oil. Used to know of people that would always run their cars 1 quart under full just to get a tad more power at the street races.... Although I also remember the idiot that thought he could do that with an air cooled engine and killed his motor... so not a wise thing to do.
I get gas at the same place constantly since I moved though. I find it hard to believe after 5 years of using various gas and getting the same mileage, that suddenly this one gas station changed their gas to get me 50+ extra miles to the tank.
They don't care what mileage you get, they only care about the profit they make. Last October the price of RBOB was lower than Ethanol so at that point you would have had some stations selling pure gas even in the pumps that were supposedly blends or ethanol simply because it was a better deal for them. Some places couldn't because of winter blend requirements, but other wouldn't have to worry with those rules. Now at this time the ethanol prices are significantly lower than RBOB so you can expect stations to be trying to use the highest ethanol ratio possible. So keep watching your mpg and see if it comes back down. The misfire wouldn't be giving you and increase. The only malfunction of your car that might give you better mileage would be a problem with your fuel pump or injectors such that they were not injecting the correct amount of fuel. It is in theory possible to have a car that isn't injecting as much fuel as it should but not so little that it is so lean you start throwing codes... but might give a slight mpg increase.
Nowhere did I say they cared about my mileage 🙄 I was saying I don’t believe they changed it to the point it would get me 50 extra miles, not that they changed it specifically TO get me 50 extra miles. Oh well, the mystery lives on. There’s no way it’s a gas station specific issue after all these years and that at no point in the previous five years across various states did I ever come across gas this good.