fuel economy

[jzeller]

When riding my 1995 R1100R in states that have low octane fuel such as Colorado where the octane is 85, my fuel economy increases by 20% or more from a general average of 48 mpg to as high as 62. My riding habits are the same as in Idaho where I live. Any insight into this phenomena?

[kbasa]

Altitude? A feedback loop might read that there's not much oxygen available and lean the mixture pretty heavily.

I got 50mpg while I rode across Colorado last month and that's the only explanation I could come up with.

Is there much difference between the altitude where you live and where you ride in Colorado?

[jzeller]

Generally the low octane fuels are sold when altitudes exceed 5000 feet. In Idaho I usually ride in altitudes between 1500 and 4500 feet. Recently in the Yellowstone/Teton area and the San Juan Skyway in southwest Colorago I consistently got over 50 mpg. Both areas are 6500 to 11,000 feet.

I concur that it has something to do with oxygen sensing, perhaps in the Motronic system with both altitude and the oxygenated fuels impacting injection levels. In my youth when riding Triumphs in the Rockies I had to change out the jets when exceeding 5000 feet in order to keep from running so rich it fouled the plugs.

I do not notice a drop off in performance, in part because an R1100R is not exactly a sport bike and I ride with some caution but rarely with the intent to conserve fuel.

A correction my average fuel economy is 42 mpg not 48 thus when I approach 60 mpg it is startling.

[kbasa]

I suppose that if I'd managed to keep the rpms somewhere south of 5K rpms, I might have seen better mileage....

:eek

[lorazepam]

Dang you make me feel like an old man Dave, I dont mind ridng all day and never getting to 5.5K. I guess I have had enough excitement in my life, and dont mind getting 50mpg at 850ft altitude where I live.

He who ambles along smelling the roses and cow poop.......

[kbasa]

Originally posted by lorazepam
Dang you make me feel like an old man Dave, I dont mind ridng all day and never getting to 5.5K. I guess I have had enough excitement in my life, and dont mind getting 50mpg at 850ft altitude where I live.

He who ambles along smelling the roses and cow poop.......

:dunno

They just seem happier when you rev the wheee out of them.

:evil

[lorazepam]

Guess I will get a bottle of testosterol and try running my little 850 a bit harder then :p

[Mr. Frank]

Another couple of factors at altitude are reduced wind resistance from less dense air and sometimes slower speeds from mountainous roads. Both can result in better mileage.

[lorazepam]

Hey Dave,

You will be proud of me. I rode yesterday, and kept the R's above 5K the whole time. I had a blast doing it riding some of the nice sweeping roads we have here in southern Ohio. I got 41 mpg, and rode home in a really nasty storm, got dry and then 3 miles from home the bottom dropped out again. So much for a clean bike.

[kbasa]

I bet that dirty motorcycle is sitting out in the garage wagging its tail.

[moterbiker]

We went to TWO amd other places the week before riding up to WVA this year, whenever we get in to the "aggressive" mode on real tight mountain roads we both laughed that the tach almost never drops below 6k even if we are in first gear on a tight corner, I love the way a twins engine keeps the speed under control just be judicious about closing the throttle carefully :D