Octane rating - which fuel for bikes?

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#11 Unread post by **nelamvr6** » Tue Jun 28, 2005 6:12 am

I always run premium. I believe my bike runs better, but I'm not sure I could prove.

But since I'm only buying at most 3.5 gallons a pop the higher price is absolutely no deterrent at all. I don't even notice it.

Aggroton · #12 Unread post by **Aggroton** » Tue Jun 28, 2005 6:19 am

yeah we hit up the sunoco alot...

there is a little gas station in my town that sells race fuel...but i think thats like ethynol or something odd like that...there are 2 dirt tracks for sprint cars around here...i think thats who's buying the stuff...

Gummiente · Tue Jun 28, 2005 6:24 am

Aggroton wrote:there is a little gas station in my town that sells race fuel...but i think thats like ethynol or something odd like that

AVGAS (aviation fule), actually. Used it when I used to race stock cars back in the early 90's, the stuff available at the track was 120 octane and oh, did the car ever run sweet with it! But even then it was $1.20CDN per litre.

TechTMW · #14 Unread post by **TechTMW** » Tue Jun 28, 2005 7:35 am

There are 2 octane ratings, RON and MON ... Most pump gas in the US is rated as the average of both (RON + MON)/2. Ducati's recommendation for "at least" 95 octane is the RON rating ... which tends to be higher than the MON rating.

To make a long story short, 92 octane is fine for the Monster.

As for Gummiente's question ... Go with what you can get away with ... carefully. For older bikes and designs, Higher octane tends to work better because the higher octane Gasoline has similar burn characteristics to leaded fuel. Harleys, for example, were designed in the stone ages when leaded fuel was the norm, and I don't think anyone in H-D engineering has figured out the fuel is no longer leaded yet!

I'm JUST KIDDING

Here's a link to fascinate/bore you to death -
http://www.cs.uu.nl/wais/html/na-dir/au ... part3.html

You should initially be guided by the vehicle manufacturer's recommendations, however you can experiment, as the variations in vehicle tolerances can mean that Octane Number Requirement for a given vehicle model can range over 6 Octane Numbers. Caution should be used, and remember to compensate if the conditions change, such as carrying more people or driving in different ambient conditions. You can often reduce the octane of the fuel you use in winter because the temperature decrease and possible humidity changes may significantly reduce the octane requirement of the engine.

Gummiente · Tue Jun 28, 2005 7:41 am

TechBMW wrote:Harleys, for example, were designed in the stone ages when leaded fuel was the norm, and I don't think anyone in H-D engineering has figured out the fuel is no longer leaded yet!

I'm JUST KIDDING

Too late, you already hurt my feelings.

earwig · #16 Unread post by **earwig** » Tue Jun 28, 2005 8:06 am

My manual on my Honda says to run at least 86 octane, so I run regular with no problems.

ronboskz650sr · Tue Jun 28, 2005 8:30 am

My 26 year old bike runs best on 87 octane...at 45-50 mpg. It fouls the plugs around town on premium and only gets 35 mpg, but I don't think it would on a trip. Older technology, lower compression, blah, blah, blah...oh, and it really hates gas with ethanol. No clue why.

honda599 · #18 Unread post by **honda599** » Tue Jun 28, 2005 4:43 pm

Look, you hurt Gummiente's feelings and made him cry

tristan_s · Tue Jun 28, 2005 5:20 pm

well, in terms of cars... i used to drive a VW with a 2.0 engine that could burn 87 octane no problem. you *did* notice a teeny difference in performance but it wasn't that much, and the 2.0 is an international market engine that is intended to be run in countries in Central America and Eastern Europe where peoples' economic status dictates what kind of gas is available (i.e. usually low octane).

so i traded up to a 2.8l six a year or so later and it recommended a minimum 91 Octane, with 93 being better. It's a higher performance engine built for the US/EU market and so I figured I'd stick to that. My g/f put 87 in once because it "didn't matter," and the car ran like it was ready to kick off. it pinged, the Check Engine light went off... yeeow.

In California we get 91 as our Premium and 87 as regular. Back in Boston you could get 93. it's just state regulations that dictates that.

so there's some validity to stating that a vehicle "must" use a certain type of gas and regardless of what you may hear from your grandpa the IS a difference between octane ratings (no offense to any grandpas here, just from my experience in the automotive business, i met a lot of older guys who said their new cars were "junk" because they had engine problems at 20k mi, because they'd never put the recommended fuel rating in the tank before). if you really want to figure it out, burn a tank of lower grade fuel and see how it runs; a few tanks won't hurt you unless you have a serious race-tuned engine.

Wizzard · #20 Unread post by **Wizzard** » Tue Jun 28, 2005 5:38 pm

I've never run anything but Premium in my scoots . When I lived in the desert on the Colorado River one of the stations in town carried Av Gas for the Jet boats and so I ran that consisently in my old trusty slimey limey .
And even now I run Premium in my Camaro and I keep track of my milage and I do get , not only , better gas milage , but better preformance as well .
And I've even gone as far as adding Lacquer thinner to my gas in some of my older scoots . Did a much better job of boosting octane than the commercial octane boosters .
Wouldn't recommend it for the newer rides out there now tho .
Kind regards, Wizzard