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E85 and Spark Plug Heat Range

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I keep seeing conflicting information everywhere, some people say E85 is more prone to preignition than pump gas so its necessary to run a colder plug because if the plug tip is too hot it could preignite the E85 easily. Others say E85 burns cooler than pump gas and it would be beneficial to run a warmer plug because the cooler mixture can self extinguish because the tip temperature is too cold.

Which of these statements is closer to the truth? In my experience E85 has been a much more forgiving fuel to tune on than pump gas.

Hello, I generally start by using the exact same plug and read the plug while on the dyno to make the call to which heat range to use.

The attached web page is one of the most accurate bits of plug reading information I have ever read and I've been tuning and reading this sort of material for 34 years


Regards Ross

^^^^That is one the most lovely web pages I've ever been too, fuckn, thanks for sharing, much mahalos.

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