Do not understand how Alternator low voltage load increase MPG.

[DarbyWalters]

Originally Posted by 8307c4

Now I can't remember if this would be practical for anything but racing.
But you might check into some aluminum / high performance pulleys...?
They're not cheap thou, and reading up on it is fairly required.

As a general rule they weigh less, also in some cases they're a different diameter, the idea being that it reduces the accessory's rpm some.

In racing you change pulley sizes on the crank, waterpump. alternator to slow down the water pump to prevent cavitation at high rpms and lower the alternator draw at high rpms. Increases horsepower...usually run no fans except in 12 and 24 hour enduros for the same reason.