On Saturday 18 September 2010 11:25:08 you wrote:
> Hey Andy, Family guy :-) You just hit part of my questions. This car from
> the Dark side :-) chevy cobalt has litres per/ 100 km indicator. Non
> ethanol gas seems to go further.
I haven't seen non-ethanol gas at the pumps in 20+ years here.
The reason you get less mpg with ethanol is because burning it releases less
energy than burning gasoline. So, for a given milage, you need more of it to
get you there. The benefit to ethanol is that it's (sometimes) cheaper than
gas, so blending it brings the cost/gallon (litre) down a bit, and with a weak
blend (10-15%) the milage isn't significantly reduced.
Ethanol was cheaper a few years ago. Bumper crops of corn reduce the price of
the grain used to make it. Then things like E85 and $100+/barrel oil came
along, and corn prices shot through the roof, also increasing the price of
ethanol to the point where E85 no longer makes economic sense. But, because it
keeps corn prices up, it's popular with farmers and politicians.
You could check with the manufacturer, but most cars produced since the 1980s
were built with the seals and hoses needed to run on 10-15% ethanol without
problems.
For dragstrip performance, you might be better off with a non-ethanol fuel.
Depends on your engine, and can probably only be confirmed with good record
keeping and testing one vs. the other. Lower octane explodes easier,
basically. Higher octane resists exploding. So for a high compression ratio,
or forced induction (blower, turbo) engine, you need the higher octane rating
to reduce the tendency toward pre-ignition (detonation, knocking, etc.). But
given a fuel with "enough" octane rating to keep the engine from pre-ignition,
having fuel with a higher octane rating doesn't do any good and may actually
hurt slightly.
Ethanol in the fuel could be helping you a different way, though. When it
atomizes in the intake track, it absorbs energy (heat) from the intake charge.
This can lead to a slightly denser charge, allowing more air (and fuel)
through the engine.
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