There is a problem when comparing Octane numbers in Europe with the USA, as they are slightly different, Google says. Europe uses RON (Research Octane Number) and the USA uses MON (Motor Octane Number) or PON (Pump Octane Number). It means that 93PON is equivalent to 98RON. The S&S info that says to use minimum of 91 Octane means 91PON in the USA (probably?) and that equates to 95RON in Europe, which seems sensible. I use 98RON whenever I can but use 95 otherwise, no problems with either.
