Race Gas vs Pump Gas..mix?

[davewadd]

I recently bought a 1975 911 with an '87 3.2 motor. The previous owner used the car only for track use.

The motor is a 3.2, with PMO carbs. The previous owner was running 110 octane race gas. Aside from being a carb car, and not fuel injected, the motor is a stock 3.2, and the previous owner did not make any adjustments to the timing for the race gas. He just said he thought it ran better with the race gas.
At $12/gallon, I'd prefer to run premium pump gas..plus it's easier to get..

Is there any reason I can't run pump gas? Can I mix unleaded into a tank of leaded race gas?

[Zuluracerx]

Yeah, run 91 and you will be fine with stock ecu. Only need higher octane if you are running high advance on your timing and/or extreme heat conditions (and of course if you are boosting with a turbo or SC or raising the compression somehow higher than stock)...but seriously you need a race map to benefit from the 110 and all the map would do for a carb motor would be advance the timing.

[davewadd]

thanks for the feedback... Is it ok to mix unleaded into a tank of leaded gas?

[RSTarga]

yes you can mix.

[nickd]

I mix leaded race fuel and normal pump gas - mfi pump enjoys a little lead ..