[Brian]

AFAIK, a higher octane rating in and of itself shouldn't result in higher performance in an engine that runs well on lower octane.

However it's possible that the lower octane fuel is also mixed with ethenol as a cost cutting method, and ethenol -- although it reduces pollution when added to gasoline -- has a lower specific energy than gas.

Of course, I'm not an automotive engineer, and maybe my information is incorrect. Some have reported better acceleration with Premium, others have reported rough idling and misfiring at moderate speeds with it.

Try different brands and different grades, and buy what works best with your particular bike and riding style, I guess.

 

[Brian]

87 octane fuel at my local Arco station went from $2.30 a couple of weeks ago to $1.99 as of last night, and I assume other grades dropped in price as well (since I've always bought 87 I haven't really paid attention to the others).

Maybe I'll try a few tanks of 89 and a few of 92 and see what my results are. I'll post them here when I've tabulated my cost per mile figures.

 

[Brian]

Re: High octane...better performance? No

...See http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

Thanks for the link. It's good to know what the "official" position is.

For more on the unofficial position see the discussion in the Burgman 650 forum under "gas mileage."

http://burgmanusa.com/forums/viewtopic.php?t=1411&start=15

 

[Brian]

...But I won't run it in any of my vehicles - based on articles I've read in the past that argued that the alcohol is not really good to put in a vehicle. I think it had something to do with causing fuel lines and gaskets to deteriorate over time - I don't remember exactly. Anyway, back when I read those articles, I made a mental note to avoid that stuff. ...

I double checked my Owner's Manual, and Suzuki says you can run gasohol with up to 10% ethenol (grain alcohol) or 5% methanol (wood alcohol). Or MTBE up to 15%. (It's either/or -- MTBE is not used as an oxygenator when alcohol is used.)

They add a strong warning about methanol: "DO NOT USE fuels containing more than 5% methanol under any circumstances. Fuel system damage or motorcycle performance problems resulting from the use of such fuels are not the responsibility of Suzuki and may not be covered under the New Vehicle Limited Warranty or the Emission Control System Warranty."

Based on that warning, I'd avoid any methanol just to be safe.

Here in Washington, gas pumps are required to have a label indicating what oxygenating additives are used and to what percentage, but not all states do so. If you don't see it, ask...but be prepared for shrugs and "I dunno" from most attendants.

 

[Brian]

...One of my friends had a '51 ford coupe. Offenhauser 11:1 high compression heads on a '53 Merc flathead V-8. Hot cam, 3 deuces, Mallory dual point ignition, etc. The only gas that thing would run on was Sunoco 260 (highest pump octane available). It would still ping occassionally. ...

"Back in the day" I had a 1969 Pontiac GTO that was pretty well tricked out. Unless I kept my foot out of it, it would ping mercilessly on any regularly obtained gasoline grade. Since I had a lead foot that might have presented a problem, but I had a ready supply of 100 octane avgas (aviation gasoline) available -- for a price. It worked "really sweet" as the kids would say. Unfortunately I only had it for a little over a year when I got forced off the road in the snow by a nut-case in a Jeep. I ran square on into a big oak tree. Turned the "outy" on the grill into an "iny" of major proportions. I really miss the old goat.

 

[Brian]

And don't forget, at 35 cents a gallon it was full service and you got your windshield cleaned and oil checked in the process!

I remember 23 cent/gallon gas. I also remember earning 85 cents an hour at my after-school job as a pin chaser at a bowling alley.

If that ratio still held up, gas would be $3.75 per gallon, so it's actually cheaper for me now in relative dollars.

Doing that comparison was a real eye opener. :shock: