Regular Unleaded in an R1200RT?

[Professor]

A friend drives an Accura. Premium fuel is recommended, but he has used only regular unleaded for about 80,000 miles without a problem or a ping. He says that the engine electronics compensates and there is no need for premium.

I remember reading that the RT also has some circuitry that compensates for lower octane fuel. Has anyone been running regular in their RT? Any consequences - real or potential?

I'm sure something has been posted on this before, but several searches found nothing.

[Motorwerk]

Regular unleaded is fine in the R12xx series there's no harm done using it. The knock sensor will compensate if there's any indication of pinging, which is something the R11xx series is lacking.

Keep in mind that your mileage may drop a bit due to the drop in horsepower so it's probably more economical, even with higher prices to use a higher octane fuel.

The HP rating is derived from the use of high octane fuel probably, even higher than what we have in the US.

[Vagabird]

Regular unleaded is fine in the R12xx series there's no harm done using it. The knock sensor will compensate if there's any indication of pinging, which is something the R11xx series is lacking.

Keep in mind that your mileage may drop a bit due to the drop in horsepower so it's probably more economical, even with higher prices to use a higher octane fuel.

The HP rating is derived from the use of high octane fuel probably, even higher than what we have in the US.

:thumb What he said. When I've had to use regular in an R12, I get noticeably worse mileage. (Sometimes you'll hit a station with only two pumps: regular and diesel.) The bike runs fine on regular, it just doesn't have the power or get the mileage.

[fracture]

My owner's manual specifies 98 ROZ/RON, Super Plus unleaded. Alternate is 95 ROZ/RON Super unleaded, can be used with reduced performance and consumption. (I think they mean greater consumption, i.e. worse mileage).

These numbers are European octane ratings and I do not think they are the same as U. S. octane rating numbers. Is it safe to say that the 98 ROZ/RON is equivalent to U. S. 93 octane rating?

In the end, it is the cost per mile that matters. Cheaper fuel, less mpg. Higher octane, better performance, better mpg. Looks like the cost per mile would be about the same.

[AKBeemer]

There is no fuel sold within 350 miles of me that is higher than 90 octane and when riding the road to the lower 48 there are many areas where only regular is available. I've had no pinging and get mileage in the high 40s low 50s. Last time I had my bike serviced they did a computer upgrade that was supposed to help it run on lower octane fuel without precombustion issues.

[marchyman]

These numbers are European octane ratings and I do not think they are the same as U. S. octane rating numbers. Is it safe to say that the 98 ROZ/RON is equivalent to U. S. 93 octane rating?

Pretty close. The RON is about MON + 10 and in the US the AKI (Anti Knock Index) is (RON + MON) / 2. Here in the SF bay area the highest AKI you're going to find at the corner gas station is 91. The three grades usually provided are 87, 89, and 91. If you look hard you might find higher.

It's interesting to note that the required grade is something about which BMW can't make up its mind! I don't remember what the users guide for my '05 GS says, but there is a decal around the filler that says to use an AKI of 89 or better. If you do a little more looking you'll find a sticker on the gas tank that says use 91 or better. So which is it, BMW :deal

No wonder owners are confused.

// marc