[graydonengineering]

Nearly all modern engines, especialy smaller ones, are interference type. Plus, if your belt/chain is stretched far enough, it will exceed the limit of you tensioner travel and as a result have inconsitand variable timeing that is impossable to adjust propperly leading to poor performance.

The last 3 Nissans I have owned do not call for a sceduled replacement at all. They run a chain that is expected to lest the life of the motor. I would assume that would be a "normal life" of less than 200K. If I exceeded that, I would replace it anyway just to be on the safe side. Most cars and trucks call for a 60k replacement. Check your specs. You can push it a little depending on how you drive but do forget about it all together. Age alone will take it's toll on those rubber belts.