BMW R1200RT/R1250RT Forum

I'm getting my r1200rt (2005) in a week just wondered if its better to run on premium unleaded or the standard stuff? Cheers

David. wrote: ↑Mon Feb 27, 2023 2:45 pm

Cheers. I was just looking for which people would recommend? Does the bike respond well to premium or not? In my experience some vehicles thrive on it and some don't.

Windy wrote: ↑Mon Feb 27, 2023 2:59 pmI was just looking for which people would recommend. Does the bike respond well to premium or not.

Most of the time, I use Tesco Momentum 99 (E5). IMO, it's unlikely you'll feel any performance difference but may see better MPG. Then there is the debate between supermarket fuel and branded (E5 or E10).

Some further discussion in this Fuel Grade thread, viewtopic.php?t=1252&hilit=fuel+grade

I used the posh stuff until the prices went crazy then I went to standard, tbh I don’t notice the difference other than at the till!

AFAIK, the standard stuff is recommended for a Wethead.

Run on normal E10

Your bike needs to be tuned to 99 octane fuel to get the best out of it

I have used both and can tell no difference

sakm wrote: ↑Mon Feb 27, 2023 5:40 pmYour bike needs to be tuned to 99 octane fuel to get the best out of it.

What does that entail.

David. wrote: ↑Mon Feb 27, 2023 5:50 pm What does that entail.

A full tank f high octane fuel and a day on a dyno and someone tweaking the fuel maps and timing to get the best out of the fuel and bike

But for our bikes it's not worth it as the gains for road use are not really seen

Just dug out some guidelines I was given before taking my Camhead to be remapped.

"Super unleaded fuel - unless your bike's manual specifies that the engine will give maximum performance on super unleaded, there is no benefit to filling up with super unleaded before your visit. We tune to standard 95RON fuel as it's commonly avialble. That doesn't mean you shouldn't use super unleaded where possible, as it often has other benefits such as better detergents and less ethanol than standard fuel, but you won't get more power with our tune from doing so."

Other engine tuners may have a different opinion.

AFAIK, octane rating is determined by the engine compression ratio and doesn't enhance performance. However, using a lower than specified octane ratio may cause pre-ignition/pinking. Modern bikes have anti-knock sensors, hence the Camhead and Hexhead being capable of running on lower octane fuel.