Are billet aluminum underdrive pulleys 'better' than steel underdrive pulleys? :feedback

Aluminum would be lighter I believe. . .

JP, absolutely...depending on your definition of "better". Lighter=less rotational mass to move, and less sprung weight. Allows the engine to utilize its torque/hp more efficiently.

however, aluminum pulleys dont hold up so well under extreme conditions, i.e. impact, belt slap, heat exchange, moisture, etc.

if you encounter a 'worst case scenario" under the hood, the pulleys will be compromised due to their softer material.

if you do go aluminum...just keep an eye on their "trueness", and check them often for any signs of damage(road debris, etc).

I am willing to bet that the difference would be hardly noticeable in a 4000 lb car with a stock engine though...best save the money for those tires you plan to waste quickly!