What exactly is different about the timing belt procedure/maintanence between the pre-87 and 87-onwards models? I'm very close to buying my first 944, an '87. I read something about an auto tensioner in the 87 and later models. Does this still require the tensioning tool for maintanence and belt changes?

 

The 87 and later have the spring tensioners, which will put the tension on the belt itself. The 86 and newer you adjust the tension with a wrench and then tighten down the locking nut. Both still require the tensioning tool. The spring tensioner will get it close, but is not always 100% accurate.

 

so it tends to stay tight better than the early models, but still requires the guage for safety?

 

No, the belt is tensioned to the same spec via both tensioners. It is wise not to put a lot of trust in the 20 year old spring tensioner, which is why you always check your tension. After you have done it a few times with the gauge, you get to a point where you can check the tension using the 90 degree twist method and get pretty close without the P9201 tension tool. You still lock the spring tensioner down with a locknut after you get the tension set on it.