The best replacement for serpentine belt is timing belt.

The best alternatives to serpentine belt are rated as following:
★★★★★  timing belt
★★  drive belt
★★  fan belt
★★  v belt
★  alternator belt
★  accessory belt
  timing chain
  power steering belt
  alternator
  v-belt
  cambelt
  goodyear serpentine belt

Your alternative for serpentine belt is not listed? Suggest!
Speaking about serpentine belt, one probably shouldn't forget about tensioner.

Other search terms related to serpentine belt and their ratings are:
★★★★★ tensioner
You have in mind a companion for serpentine belt and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of serpentine belt in all years. Click on graph for more.
serpentine belt
timing belt
drive belt