2011 Toyota Tacoma Regular Cab Owners Manual - Page 520
2011 Toyota Tacoma Regular Cab Manual
Page 520 highlights
6-1. Specifications Fuel information Your vehicle must use only unleaded gasoline. Select octane rating 87 (Research Octane Number 91) or higher. Use of unleaded gasoline with an octane rating lower than 87 may result in engine knocking. Persistent knocking can lead to engine damage. At minimum, the gasoline you use should meet the specifications of ASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada.