Would high compression pistons help fuel mileage?

[Mike Caldwell]

Since my 401 will need new pistons I'm wondering if custom pistons with a higher compression ratio help me get better fuel mileage?

[Prowbar]

Yes. More power, better fuel mileage generally.

[Mike Caldwell]

What about supercharging? What would adding a reasonable amount of boost do to efficiency of our low-compression beasts? (Twin screw for low speeds, not turbo or centrifugal)