so.... does putting 93 octane in my car cause engine knocking? or affect the compression ratio in a bad way to eventually lead to engine knocking? or is it if u put 87 octane that the compression ratios are affected negatively and engine knocking occurs....? sumone tell me what Ford as well as Mustang drivers recommend for fuel octane.....

 

If your car is stock, put the regular 87 or 91 sometimes, no need for 93 it will leave some gas particles that havnt burnt, but if you get a tune for 93 and put 87 then knocking can occurs because the gas particles can burn BEFORE the spark (pre ignition)

 

LoLo is 100% correct on that. Run a search on this for more detail. I know I've seen a few threads on this.

 

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