Regular unleaded is 95 over here, super is 98 and Shell recently brought out Optimax which is 99. I think the ratings are different. Martin #1458 theshovel1224 wrote: > I think the 91 in the manual refers to 91 in British gas, > which is different than U.S. > I have always run mine on 87 w/o any problems. > > John Yeoman