I'm curious about fuel mpg. Some engines have timing systems that advance the timing till it knocks then backs it off a little. Another post claimed maximum advance gives more hp and mph. The main difference between 93 and 89 octane fuel is the predetination additive. Does this mean you can run more timing advance with 93? If so, will you get enough fuel mpg increase to pay for the higher priced fuel? I did some math with $2.80 per gal 89 and $3.00 per gal 93 octane. If can get 2 more mpg with 93, I think it will pay for the difference.

Do new Mustangs have this type of timing system?

 

I have a Steeda timing adjuster set at +3* and got a two MPG increase while running 87.The engines that adjust their own timing have knock sensors.Knock sensors are only available on the 4 valve versions of the 4.6.

 

[sm=headbang.gif]Real bummer![sm=headbang.gif]



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