[Mgs] Overdrive Numbers

[Paul Hunt]

For the same timing setting on our cars there is indeed no benefit to be 
gained by using a higher octane fuel.  But if you *do* use a higher octane, 
you can advance the timing and that *does* give you the benefit of more 
performance and better economy.  Many modern high-performance cars use 
knock-sensing to continually fine-tune the timing and they also get better 
performance out of higher octane fuels, but automatically.  Others running 
on fixed maps will not get any benefit.

PaulH.

----- Original Message ----- 
> Paul, there's also the urban legend that high octane
> fuel equals high power.  Many people run their
> 89-octane-designed cars on 93 octane fuel, at 20-30
> cents a gallon more, expecting superior performance.