This is one of those questions that you're going to get a bunch of first hand, very smart, very experienced people with exactly opposite opinions. I only fit the first hand experience thing, but here it is. I put one in and ran a new rollmaster chain with billet sprockets. Ran the car 3-4 years up until last winter and pulled it apart. The spring side guide was broken at the pivot, the flat spring slid down to the bottom of the cover between the bottom sprocket and the cover on disassembly. The spring had almost eaten its way through the cover. The guide was not worn through or oil starved. I will not run another tensioner.