Originally Posted by Jafro
Some people mix alcohol into their water injection systems. It keeps it from freezing up in the winter, and since ambient temps are lower, your engine is already cooler. If you're not close to the knock ceiling, (keeping exhaust temps well under 850°C), then you'll be able to make a few more horsepower by adding alcohol. But the inert gas which is water vapor actually does just fine at increasing your compression while lowering combustion chamber temps.
My roomie runs 50:50 alcohol and water in the winter, and all water in the summer, it never really made a difference in power, but you might have to do some playing on a dyno to really figure out if it can. Also, windshield fluid works well in a pinch too
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