Say What again!
Join Date: Sep 2009
Location: Washington Township, Michigan
No Cobalt engine was sold as a Flex Fuel engine - therefore, you cannot safely run E85 in your engine.
It won't ruin anything (anything since the mid-80s is equipped to handle any amount of ethanol in fuel), but the engine will absolutely not run properly. While E85 is technically 105 octane, you also need to use about twice the amount as "normal" gasoline, as the amount of energy contained in each molecule is much less.
So, your engine is likely going to retard timing to an extreme degree to try and prevent engine knock as much as possible, which will make it run much less than efficient - you may notice a drop in available power, as well as far lower fuel efficiency.
In the future - do not put E85 in the car, unless you're specifically tuned for it.
Out of curiosity, why did you want to try E85 in the vehicle? It may be cheaper per gallon, but due to what I mentioned above (less amount of energy per gallon than gas), you'd experience a decent drop in fuel economy, even if you were tuned for it.
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1998 Chevrolet Cavalier - Wrecked/Donated
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