The best replacement for unleaded is super unleaded.

The best alternatives to unleaded are rated as following:
★★★★★  super unleaded
★★★★★  diesel
★★★★  premium
★★★★  leaded
★★  premium gas
★★  leaded gasoline
★★  leaded fuel
★★  premium gasoline
★  e85
★  unleaded plus
★  unleaded
★  premium unleaded
★  regular unleaded
★  plus
★  diesel prices
★  e10
★  lrp
★  premium fuel
★  premium petrol
★  unleaded premium
★  leaded petrol
  ethanol
  super unleaded gas
  mid grade
  regular gas
  v-power
  v power
  super
  leaded gas
  premium unleaded petrol
  xcs

Your alternative for unleaded is not listed? Suggest!
Speaking about unleaded, one probably shouldn't forget about e85.

Other search terms related to unleaded and their ratings are:
★★★★★ e85
★★★ e10
★ leaded
ethanol85
You have in mind a companion for unleaded and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of unleaded in all years. Click on graph for more.
unleaded
super unleaded
diesel