[Hal Copple]

I can tell precisely when Upstate SC begins the "winter gas" in the fall, and when i get my first fill of "summer gas" in the spring, where i live, about early April. Winter gas has a higher Reid Vapor pressure, for easier starting in older, carb cars.

But on my car, it only makes for carb percolation and boil over, and hard starting on a re-start if my engine has sat for over about 15 minutes, or enough to boil all the gas out of the carb. Even with a heat shield and a half inch phenolic spacer. If my car is sitting in warm temps, in traffic for an extended time, with the winter gas, it will boil over, and flood-my engine, so i have to race my motor just to burn it out, and get new cooler gas into the carb.

I don't think it carried less heat energy, but it sure can make a hot carburated V8 a bit of a trick to run in traffic on a relatively warm winter day.

On the other hand, it does make for lots of attention getting throttle blips!