Here's what I found on Taco Bill's take on UDP's

"By changing the size of the Crank pulley, you are effectively changing the “gear ratio” of the crank pulley to the rest of the pulleys it drives. You are both slowing them down and giving the crank more mechanical advantage over those other pulleys. More mechanical advantage means it takes the pulley less work to turn everything. The end result is that there is less parasitic drag on the crankshaft and more being send to the wheels."

I'm thinkin of getting UDP's, but my question does new UDP's like from BBK or Granatelli, increase the longevity of the engine? "More mechanical advantage means it takes the pulley less work to turn everything." Anybody have technical insight.

 

I'm guessing that the engine would be working a little easier at the same speeds with the udps or when accelerating at the same rate. So, in theory, the engine should last longer. I would assume it would be negligible in the real world however. Again, I'm just guessing....