Are underdrive pulley such as the UUC Ultimate Underdrive Pulleys a good performance mod? Sometimes I hear they are a worthwhile upgrade that will help increase power and other times I hear they can make your motor work to hard and eventually ruin it. Is it a worthwhile investment for my 1997 328is and what kind of difference would they make in the performance of my car? Thanks for any advice you can give. ![Wink [;)] [;)]](/images/smilies/wink.png)
![Wink [;)] [;)]](/images/smilies/wink.png)