[Brian894X4]

Based on the 1993 article about the "new" 1FZ's engine management system and my limited knowledge of octane and engines, this appears to be what's going on....correct me if I'm wrong....

Even though 9 to 1 compression seems low by today's standards, it's really not that low and most engines are only able to run on the standard octane gas, because the timing is retarded to prevent pinging and other issues, which is where power is lost.

The 1FZ with its duel knock sensors and new engine management system can run the higher octane fuel with the engine timing advanced and providing more power and possibly smoother operation, while the duel knock sensors prevent damage by sensor potential problems from all 6 cylinders. Since the engine can run more advanced, there is more power.

It's not about more energy or less energy in the different octane fuels giving more power, it's about whether or not the engine can run at peak effeciency and more advanced timing without risking damage.

Also, another thing to consider. Small piston aircraft gas engines use 100 or 130 octane fuel, yet have fairly low 6 or 7 to 1 compression ratios on many models.

By the way, my 22RE pings like a mad monkey on low octane fuel. But part of the problem, I'm sure, is carbon deposits on the pistons over the years, even though I've cleaned out the combustion chambers multiple times.