Quote:
Originally Posted by JoeD
Highest performance will be achieved on the lowest octane fuel possible without knock. If you run 87-octane and the engine does not knock/ping, then it will run better than if you had filled 91+.
|
True.
You have to remember that, with modern cars, the ECU will dial back timing to prevent knock/ping. If you put 87, it will dial timing back and reduce performance but it will be fine. On the flip side, if you put 91, it will advance timing to give greater performance.
Now the unknown is: what octane is necessary for the ECU to advance timing to the MAX? Timing from manufactures might be designed around 91-gas as a requirement but is it really "optimized"? Is their untapped potential?
Silly analogy but it's kind of like how you can overclock CPUs to realize performance gains over stock by simply advancing the timing. The CPU is marketed and rated at 3.0GHz but it can go higher.