Chevy & GMC Vans

I put some gas in my van that had ethanol in it... My mileage went from 19-21 mpg to about 11-14 mpg, even on the highway. I've been careful to only use non-ethanol fuel, but the mileage is still not coming back. How do I fix this? Someone says the only solution is to run it out, and it takes a lot of non-ethanol fuel to do it. Is there any other way?

Btw, I know it's not the tires, because I have them all at about 44 psi, and I don't have braking issues either, so I'm pretty sure it's from the gas. The only thing different in the way I drive is that I moved out of town, so now most of my driving is done at about 50-75 mph on the highway and the country roads.

Probably going to have to run it out completely.

You actually have non ethanol gas up there? Every gas station here has up to 10% ethanol. No such thing as non-ethanol.

i was wondering that myself, i assumed he meant he ran E85 since only 10 percent ethanol should not make an 8 mpg difference should it? that seems extreme and impractical

Green will get better than 20 mpg with 10% ethanol. Wonder if there is something other than gas causing the drop.

Check the O2 sensor if it is bad that will drop the mileage. They are only about $35.00. You have probably burned more than that in gas.

I only ran 10% ethanol... I used to have a Blazer with a 4.3 in it, and after using ethanol, my mileage went from 15-20 to 9. I guess that station just has bad gas. Just so nobody else gets it, the station in question is the OK One Stop on Broadway in Sulphur.

Anyway, how do I test the O2 sensor?

I too believe there might be something else going on besides a tank of bad gas. If ethanol was the problem, each additional fuel-up (w/non-ethanol) would dilute it, bringing your mileage back up a bit. If your mileage hasn't improved after a couple of fuel-ups, then I'd look for another problem. Oxygen sensor as suggested is a reasonable place to start.

10% ethanol will reduce your mileage a bit, but you shouldn't drop by half!

Out of curiosity, how are you calculating your mpg? Yours is a '92, I don't think it has an overhead display, does it? Just seeing if there is a flaw in the math and not the vehicle, that's all.

-Andrew

I've been reseting the mile counter when I put fuel in, then when I have to put fuel in again I divide the miles by the fuel used. I'm not exact on the fuel, but since I'm currently taking a math class in school I certainly hope I'm not that far off.

Using this method depends on a lot of factors such as the angle of the vehicle, temperature, and the pump itself. It's best to use the exact same nozzle every time, and let the pump shut off by itself. (don't give it the extra squeeze to top off)

Not trying to be an ass or anything but, I still think there is a different problem that is causing your mileage drop.

I run 10% ethanol in my '89 Astro and still get over 20mpg. That's even with over 1,000lbs inside the van and leaking rear shocks.

Air temp and the slightest difference of angle is not going to drop the mileage by 8 mpg.

Maybe by a tenth of a mpg but not that much even if you over filled the tank on the second fill. I still think that the O2 sensor is probably shot. Of the van was in open loop mode and running rich it could do that to the mileage.

Just got some more gas, and it averaged out to about 15, so it seems to be going back up now.

But just in case, how do I check that O2 sensor?

I watched a movie on ethanol (forgot the name) but we are truely being fleeced! The process actually uses more petroleum than the amount of ethanol produced (including the fuel for farming machinery, transport, petro-chemical fertilizers, etc.)...and as a double whammy it lowers the milage in vehicles...and as a 'triple whammy' it is heavily subsidized (taxpayers funded). Its touted as an 'alternative fuel' but it increases the amount of petroleum we use. Very frustrating that its nearly impossible to buy gas without it these days.

Around here it's not so hard to find ethanol-free gas because most people's cars won't even start with that stuff in the tank. I know of three ethanol-free stations in Sulphur, and one in Davis.

I heard a story once from a friend of mine... He says someone put gas with 10% ethanol in his truck (early 90's Chevy 2500, I think), and he barely made it across town before it started sputtering. Another person I know put 10% ethanol in his truck and it wouldn't even start. Then again, there's lots of rumors about the Sulphur gas stations. I heard they dilute their gas with water so that there's more to sell, and I also heard about a price-fixing conspiracy. And this wasn't from some aluminum-hat-trailer-nutcase, this was from one of my teachers.

I stopped buying gas in Sulphur unless I have to, and like I said, my mileage seems to be coming back. I guess the moral of this story is "don't buy gas in Sulphur."

Hopefully bad gas was the only problem. If not, I've eliminated one possible cause, and I can go on to the others.