Racing fuel in a Z

kannibul

I think that the Z is built on spec for 91 octane to run properly under all conditions, and as a safety will retard the timing if it detects a knock.

Gas that is delivered to the gas stations are "more or less" 91 - so some days you might be pumping in better than 91, other days less than 91. Depends on what gets delivered from the supplier.

If you doubt it, look at the sticker on the pump where it was tested.

Soemthing also to consider for those who top-off often. There's fuel in that hose all they way from the pump - that's about 1-3 gallons worth of whatever was put in there by the last customer. So, the first 2-6 gallons you put in are more than likely "mid grade" - 89 octane...even if the gas in the tank is on-spec, you won't reach a perfect 91 octane even if you fill up...