Most factory pulleys have a very thin rubber band sandwiched into their steel pulleys to reduce vibrations and noise.
The anti pulley scientists claim that if you remove this rubber piece your engine will fail after long term use (something like 150,000 miles or more.) These guys swear up and down that aftermarket pulleys are the work of the devil and will tear your engine into pieces. Their evidence is usually theories and formulas backed up by internet heresay and "he said, she said."
Then there are others who have actually used pulleys for years and have never had issues. These people usually outnumber the first group. I have been using NST pulleys for the past few years on several cars with no problems of any kind.
Third, there are the pulley builders who tell people that their products are safe if installed properly and won't harm your engine if you know how to maintain it properly. They sponsor cars and test their own cars. Ofcourse they are full of crap because they are only trying to sell us stuff. We shouldn't listen to them
Here are a couple of cars listed on the NST site. Would these guys really put weak sauce products on their own race cars if they knew their ish would blow up in front of their fans when they go to big events?
