In most cases this is a true statement. This is one of the reasons Honda recommends it for the S2000. All of their other engines, with the exception of CART and F1 , are not considered high reving. That was my only point regarding the Prelude and such. But combustion is the main key here and unless the octane is being used it can have negative effects. Also, why would you consider a V8 low reving?

 

The RPM that the engine turns has nothing to do with the octane required. Higher octane helps prevent detonation in high compression engines; they can be 4's, 6's or 8's. Since the Prelude runs (relatively) high compression it requires premium fuel so the ECU doesn't retard the timing because of detonation.

 

RPM has nothing to do with the octane requirement of an engine. It has to do with the timing (which is under the control of the engine computer) and the compression ratio. The heat of the engine and any carbon buildup in the engine also play a factor as well. Basically, the higher the compression ratio, the higher the octane requirement will be.

All of this is to prevent pinging or pre-ignition, which will eventually destroy your engine. I've seen tops of pistons disappear from pre-ignition. This was before engine computers were in use. Now, if the ECU (computer) senses pre-ignition, it will change (retard) your ignition timing to compensate for the problem. When you retard the timing, you loose power. I understand that our car's ECU takes a while to learn about the higher octane and compensate for it. I don't know if you will tell any difference in 2 or 3 octane rating points or not?

I hope that this helps,
Bob