octane ??

[jodann]

I know that if your engine is designed to run on regular (87 octane) it is considered a waste of $$ to move up to a mid-grade or premium.Does the same hold true when towing? Any comments?
Jodann

[jodann]

I know that if your engine is designed to run on regular (87 octane) it is considered a waste of $$ to move up to a mid-grade or premium.Does the same hold true when towing? Any comments?
Jodann

[Ray,IN]

If you begin to hear valve rattle(predetonation) under heavy loading you will probably benefit from the higher octane fuel.

[CyberVet65]

Also remember that a gas engine requires less fuel to burn at altitude.
The regular grade of gas (87 octane) works great up here in the mountains.
Chet

[RustyJC]

It really depends on your engine's electronic control unit (ECU) programming. If your ECU sets timing advance actively through a closed loop with the knock sensor, you can gain BHP/torque and improve fuel economy with higher octane fuel. This is because the ECU will continuously advance timing until knock is detected, back off a couple of degrees and repeat the process. In other words, it takes advantage of all the octane (anti-knock) characteristics of the fuel being used.

If, on the other hand, your ECU uses a map to set ignition timing as a function of RPM, throttle position, etc., then the benefit offered by the additional octane of a higher grade gasoline is wasted.

Rusty