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.

2006 R1200RT 43,000 miles.
I loive in Ca and I can tell you the stuff called Cheveron 91 barely works. The bike has a 12:1 compression ratio. Even with the dual plugs there is detonation. Gutless off the line. The stuff I use is by VP racing, 3.2oz : 1GL raises the octane to 98-99 range. Go ahead and run pump gas and then put some VP Octanium in what ever dilution you prefer. Much less knocking and a definitive change in your ingnition timing curve. It's as if a switch were thrown shut. Gone is the knock, and more robust the torque curve. Revs higher and comes up to rpm faster meaning more torque. Much more torque.
Granted the bike is not a sports bike and the max RPM is only 7000? Too many trips to redline and your adjusting your valves. But when the clutch engages around 3000rs the bike pulls as intended. Octainum works wonders only on injected bikeds with knock sensors. The reason you don't feel any difference with 87 and 98 is I don't know. I do. It's a performance machine, I treat it and ride it as such.

I only use higher octane fuel because I don’t use my bike over winter so less ethanol is better I’d assumed just sitting in the tank. I’d planned on using 95ron for the summer but due to health reasons I really don’t know if I’m suddenly not going to be able to use the bike for a while. I’ll stick with 98ron for now.

I've used premium grade & standard graded fuels in both bikes & cars, petrols & diesels and frankly I’ve never noticed any difference. I’m sure the science behind the manufacturers claims is sound, but to me the seat of the pants feeling is no different and my memory doesn’t recall me waxing lyrically to anyone about the great improvement in mpg I suddenly got.

No, I’ll keep the extra cash it costs in my pocket and use the regular stuff thank you.

I do one posh fill up to every three paupers one! I read somewhere that that’s the way to achieve the best of both worlds.

Am a tightwad. The cheaper the better.