Lets Try This Again

99greysierra · June 10, 2008

Is there a way to reprogram the ECU to compensate for the drop in MPG with 10% enthanol ? My 99 went from 20-21 HWY to 17.5 and yes I have clean oil, new filters and good plugs. Any suggestions for a solution or vendor ?

MelLandry · June 10, 2008

Are you asking if you can reprogram your ECU so that when you use ethanol you won't expereince a drop in fuel economy? All the reprograming in the world isn't going to make ethanol combustion produce any more energy than it does. If it was that simple, I'd reprogram mine to run on 10% happy thoughts.

Maybe some fine tuning will help, but you're not going to get the same milage as gas straight up.

BigJayDogg3 · June 10, 2008

But if you optimize a car to run on ethanol, it won't return the same mileage, but since it has a higher octane, you can run a higher compression engine. http://car-reviews.automobile.com/news/lot...-supercar/2058/

Texsrt4 · June 10, 2008

think about it. fuel companies are raising the prices as much as they are...plus putting in ethanol into their fuel which decreases mileage as well

aint that swell. yes its true, you can get more power with ethanol, which will allow you to run more timing or higher compression, however that requires modifying your engine (expensive). also, 10% ethanol isnt enough to allow you to get away with the higher compression. you might be able to add 2-3 degrees of timing, but thats not going to do much for you

BigJayDogg3 · June 10, 2008

Oh wait, I misread his post. I thought he was talking about E-85. My mistake. And I though at this point in time, virtually all gas was E-10.

Texsrt4 · June 10, 2008

i thought that too...but this is not the first site that i have heard issues with. i know the srt4 community is complaining big time, and the hptuners community is bringing up issues as well. maybe they raised the percentage of ethanol in the gas recently?

actually, that would make sense. before signs read something like "may contain ethanol up to 10%". but our local gas station now says "contains 10% ethanol". i bet they just raised the percentage

BigJayDogg3 · June 10, 2008

Just understood your name. DUH! Stupid me. I always wondered what the significance of the 4 was. Didn't think there were 3 other texsrt's on the site.