The calorific value of 95 and 98 RON are near identical, using 98 RON for increased power is a waste of money as you won't get any more for your money. Where you will benefit is in knock prevention as 98 RON is more resistant to detonation.
Pukmeister said:The calorific value of 95 and 98 RON are near identical, using 98 RON for increased power is a waste of money as you won't get any more for your money. Where you will benefit is in knock prevention as 98 RON is more resistant to detonation.
Outtomunch said:End result is the GS engine produces more power with 98 RON petrol over 95 RON petrol when knocking/pinking is an issue.
Mouse said:But for that to be the case, surely something must be wrong, the engine should not knock when using 95 RON fuel...
So either something is wrong with the engine, or the allegedly 95 RON fuel isn't. Maybe![]()
Ste@SSB said:As with the next best thing in life ... your right hand will never tell you lies ...

I posted the quoted section to demonstrate that you shouldn't be having a problem with knock on your R1200GS on standard UK fuel.RogerJ said:Seems a far cry from the extract of the Official Press Release on launching the 12GS provided by Zmeagol. That document seems to indicate that you can run even lower than 91 octane without a problem.
Designed for unleaded fuel (RON 95) the engine, thanks to
knock control, can also run on lesser fuel qualities (RON 91) sometimes found in other countries, without requiring any kind of manual intervention or adjustment. Within available limits, knock control adjusts the ignition angle automatically to the fuel on which the engine is running.
