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Street fuel

So I was sitting at a stoplight and the guy behind me in what looked like a 20 year old Honda, Toyota or Mazda started revving his engine. It sounded pretty good, actually. But then I smelled something familiar and it took me a while to identify it. Then I remembered that when I was a teenager I went a few times to an 1/8th mile dirt track north of town where a friend of my Dad’s used to run a quarter midget and I placed the smell: the guy behind me was burning alcohol. Which raises the question to me: what are the plusses and minuses to running an engine on the street that uses/needs alcohol?

Plusses - can run higher compression ratio, maybe a bit more power
Minuses - fuel costs more per mile, have to recalibrate the fuel system to deliver more fuel, have to replace rubber/plastic parts with ones that can handle E85.


Depending on where you live, E85 may, or may not be easily available. E85 is 15% gasoline, up to 85% ethanol. Cars built over the last 20 years have ethanol resistant fuel systems so they generally can accept E85. Actual pump E85 is more likely to be 70% or so ethanol. Octane rating rises to something like 101.

That car needs to be “tuned” to accept E85, if they are not Flex-Fuel vehicles with engine calibration changes and sometimes bigger injectors and pumps. On turbo cars, it allows much more boost pressure for better HP, plus it helps keep the engine cooler. On non-turbo cars, it allows higher compression ratios and more spark advance for more HP.

It is actually a pretty common thing around those that modify their cars. Even to the point of running about a mix of E10 and E85 to give roughly E30.

My Mustang seems to run very nicely on E30 even though it is not a flex-fuel vehicle, but E85 is not readily available near racetracks I visit for track days.

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A place in Albuquerque (not at an airport) sells 103 octane.

For how much a gallon? Unleaded race gas normally sells for $7 a gallon and more. E85 is $2.50 or so. Big difference. And it keeps the engine cooler because you need to run it so rich.

I forget and haven’t been by in months.