My 1981 Owner's Manual states: "Your De Lorean is designed to operate at factory specifications on UNLEADED GASOLINE only of at least 87 anti-knock index (R+M/2) (91 research octane number)." Here in the US the octane noted on the gas pump is R+M/2 or "anti-knock index". So, 87 octane is fine for these cars unless you've modified the motor for more horsepower. With a stock engine stay with the 87 unless you get pinging. Too high of octane means that the fuel may not burn completely and it could leave deposits in the engine. Mark N VIN 6820 At 03:18 AM 5/18/02 -0000, mccarthy410 wrote: >Hi, > >I am a new prospective owner of a DeLorean, before I buy, I'm >gathering all info I can. One question comes to mind, I know the >manual and several sites say to use 91 Octane fuel, only thing close >to it is 93, and that does get expensive. Can 87 or 89 Octane be >used with no ill effects? I'm told how the Europeans and how the U.S. >rates gasoline are two different things, any truth to this? > >Thanks.