Is that the same as "serpentine belt"? Anyhoo, I replace serp. belt at about 92000 miles. I believe it's "supposed" to be replace around 70 or 80000. Now it's at 160,000 and couple mos. ago I had timing belt replaced again. Thing is...you get no warning when it's about to go out! You could be stranded in the middle of nowhere and...KABOOM! Everything in the engine depends on that belt, so when it goes, everything goes... according to what my Daddy tells me. And he was a mechanic in the Air Force for 20 years :) He knows cars inside and out! Love that man!