Quote:
Originally Posted by cRiPpLe_rOoStEr
That's surprising to say the least. I could easily expect a car to keep its performance unchanged while using a high amount of ethanol, but not to decrease it.
Many older dedicated-ethanol cars here in Brazil actually had a lower CR, and pure ethanol (with some residual water) was used instead of E85. Most of the port-injection flexfuels also rarely go beyond 13:1.
Dedicated-ethanol (either carburettor-fed or with EFI) and earlier port-injection flexfuels in Brazil had a small auxiliary tank for gasoline, meant to be used for cold starting. Nowadays most resort to a heated fuel rail, while others have turned to direct injection which doesn't require the fuel to be pre-heated.
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Yes, most stock turbo cars, made to run on 87, have worse performance on E85. Those that run on 91-93 octane, usually have similar performance with E30, and don't perform any better, unless the boost is increased.
As far as N/A, they run worse on E85 vs 87 octane, with the exception if your engine is an atkinson engine (most atkinson engines on the market are 2.0 I4 engines). The atkinson engine can increase compression even under load to match the fuel type you're pouring in it.
I admit not knowing the exact compression ratio, but 14.7:1 seems about the max compression ratio for premium gasoline, usually used by motorcycles.
This is for 93 octane fuel. At 100-105 octane for E85, the compression can be further increased. I've read an article a while ago, with numbers as high as 16:1 for E85 compression ratio, but this was on a performance vehicle, tuned by professionals; not the average joe mechanic.
With the starting fluid, I was merely commenting on the person who had trouble starting his car on E85, but said it ran fine once warm.
At cold start, any car runs rich.
His injectors are not providing enough fuel to keep it running in sub zero temps, so he needs some combustible fluid like started fluid.