Flyboymedic

I see it all the time, folks pull into a gas station and either the attendant or they themselves, assume they need premium fuel. It's really not always necessary and you might just be wasting your money. Here's a recent article which gives an explanation: https://www.revzilla.com/common-trea...-octane-rating regarding octane rating. But it ultimately boils down to what the manufacturer recommends and it would behoove you to look in the owners manual to find out. The important piece is that RON does not equal MON and we don't use either- instead we use the average of both.

Research Octane Number (RON), used in Europe and most of the world
Motor Octane Number (MON), and where as the US octane rating is an average of (RON+MON)/2

Here is a chart I found for a quick converter to know what your bike really needs after you've check your owners manual, if it doesn't match what the US typically offers.
Octane rating conversions - PencilGeek's BMW Blog
Octane rating conversions
By PencilGeek on May 7, 2009 7:35 PM
Here's a set of conversion tables I worked up for octane ratings. The European octane rating is RON, where as the US octane rating is an average of (RON+MON)/2. The following table comes from the following web site:
http://www.btinternet.com/~madmole/R...RONMONPON.html

Actual octane rating table

EURO RON MON US: (R+M)/2
90 83 86.5
92 85 88.5
95 87 91
96 88 92
98 90 94
100 91.5 95.75
105 95 100
110 99 104.5


Formula for converting EURO to US rating
I've also come up with a pretty good formula that approximates US octane rating based on EURO RON rating, and visa versa. The formula is US=RON*(21/22):

EURO RON US (R+M)/2
90 85.9
92 87.8
95 90.7
96 91.6
98 93.5
100 95.5
105 100.2
110 105


Formula for converting US to EURO octane
And reversing that forumula, wet get: RON = US*(22/21)

US (R+M)/2 EURO RON
87 91.1
88 92.2
89 93.2
90 94.3
91 95.3
92 96.4
93 97.4
94 98.5
95 99.5
96 100.6
97 101.6
98 102.7
99 103.7
100 104.8

WarpShatner7

A few thoughts, for whatever they're worth.

• If your bike was sold in the US, then the sticker on it and the info in the rider's manual will be correct for the US.
• My R1200 hexhead boxer seems to adjust for differences in octane rating one hell of a lot better than it does for the presence of ethanol. On the occasions out on the road when I've been stuck with regular, the perceptible difference between it and premium could just about be chalked up to imagination. Not so the absence of corn effluvium, which is like getting a kick in the ass vs. a having a dog sniff it.
• The cynic in me is pretty sure this is what's usually going on under the slab at the gas pump anyway:

Ralgha

Mine wants regular, but premium is the only grade I can get without ethanol around here, so sometimes it gets that.

Didley

When I first got my R1200GSA, I rode it on the tank of gas the previous owner had put in it for about 3 or 4 days.

At the time, I didn’t realize Premium was recommended, so I filled up with regular. The next day I called the guy to ask if he always filled it with Premium because the motor seemed to be riding tougher.

Like Warp said, it’s not so obvious that you’re sure there’s a difference, but it was a big enough difference that I called the guy to ask what fuel he had used.

route246wraith

The conversion puts me between the top two grades at 90.7 (US). Pisser!

unicykle

Mine says premo so i use it, usualy only topIng off the tank with 2-3 gallons... i got the other 60 cents.

Riki5156

For all my years and around 50 specialty cars and 10 or so motorcycles I’ve never used premium except in 3 race cars. All BB Mopar one 500 inch Hemi with 15-1 compression.Other two were 11-1 440s. I used a mix with octane booster. The rest including my 83 GS1100E and 82 Seca 750 I use the cheapest ARCO regular I can get. Never an issue. My buddy can’t seem to get by with anything other than non ethanol premium on his old Buick’s. He won’t use ARCO so I kid him that it works fine for me and I even cut it occasionally with lighter fluid.

Sentinel

gas. archer-daniels.. pfft.

i almost got a tuono but they have plastic tanks and ethanol kills them quick. shame.

corn is for food. those fuckers.