I found out that the Laso brand is the OEM unit.

Lenny,

I replaced the tensioner at about 175K, maybe later than that. The factory units don't last forever either.

When it comes time to replace the belt on your car, there is a bolt that you can remove on the alternator that allows you to swing the alternator far enough to replace the belt without disturbing the tensioner. This is documented in the factory manual and someone recently pointed this out.

By changing your belt in this way, not disturbing the tensioner, you can keep the tensioner alive. It is usually the act of slackening and retightening the tensioner that takes it out, even an MB brand unit.

Good luck,