What gas do you use?

[jwhughes3]

Didnt they calculate octane numbers different 30 years ago?

John

[WSL91]

89 octane gasohol. There are a few places selling non-ethanol around here but with my variety of riding places and having 3 bikes and trying to remember whats in each I don't see where they run any different between gasohol and regular unleaded. I ran a tank of 91 a couple times and didn't notice any difference. Maybe a couple sets of dyno tests might reveal but I can't tell any difference. When it's sold the non-ethanol product is 87 octane.

[WSL91]

There is a write up in the AMA magazine this month about ethenal and how the government is trying to make it 15% alcohol now. They say that the alcohol burns hotter and it may not be a problem for water cooled engines, but the air cooled ones might get a little too hot. This means valves, exhaust, cylinders, rings and oil will be hotter.

While on the Colo Rally I ran into lots of 85 octane with 10% alcohol. I ran it and rode hard. Now the bike runs better than it ever did before the trip. Much less carbon in the cylinders and lots more power. Go figure...

I think that what really is taking place is that the government ordered a study to see if vehicles can run 15%. This was a huge thread on another forum I frequent.

[BA80]

There is a write up in the AMA magazine this month about ethenal and how the government is trying to make it 15% alcohol now. They say that the alcohol burns hotter and it may not be a problem for water cooled engines, but the air cooled ones might get a little too hot. This means valves, exhaust, cylinders, rings and oil will be hotter.

While on the Colo Rally I ran into lots of 85 octane with 10% alcohol. I ran it and rode hard. Now the bike runs better than it ever did before the trip. Much less carbon in the cylinders and lots more power. Go figure...

If you richen your mixture it will run cooler if there is an overheating problem. Alcohol does burn much cleaner and more efficiently. Drag racers and dirt track racers run a very rich ethenol fuel mixture. Rich to keep the engine cool ethenol because it increases horsepower.

[Elwood2]

I only run clear gas in my bike and the only octane around here for it is 90 and up. There are 4 stations close to me that sell it at 90 octane. Main reason they have it is for smaller engines. I've seen a few and heard way to many horror stories with the ethonal gas. If I have to run non clear gas for some reason I have this http://mystarbrite.com/startron/ that is thier website but I got it from my local saw shop

[fredintoon]

- - - Alcohol does burn much cleaner and more efficiently. - - -

Hi Greg,
depends on how you define "efficiently"
Alcohol has far less BTU/lb than gasoline and way far less than diesel fuel.
What running on straight alcohol will do is let you run an engine at a super high compression ratio so it develops way more power but you pay for that with lousy fuel mileage.
Which is OK for a race bike but not so much on the highway.

[BA80]

If you richen your mixture it will run cooler if there is an overheating problem. Alcohol does burn much cleaner and more efficiently. Drag racers and dirt track racers run a very rich ethenol fuel mixture. Rich to keep the engine cool ethenol because it increases horsepower.

Probably used the wrong word, by efficiently I meant it makes a bigger bang and yes it does take more to run and create the power.

[WSL91]

If I'm not mistaken gasoline has approx 114000 btu/gallon, ethanol 76000, and e10 is 111,800. 10% gasohol therefor has 98% of the btus as gas so fuel mileage should be somewhere in the 2% less range.
If you mileage on gas is 35mpg than with ethanol you should be seeing around 34mpg on gasohol

[BA80]

Actually riding cross country I've noticed differences from 32mpg all the way to 42mpg depending on where you are and the different blends.

Best I've ever gotten was in Iowa. That was the 42mpg

[jwhughes3]

Time slows down in Iowa so you go farther on the gas

John

[BA80]

Time slows down in Iowa so you go farther on the gas

John

So does Bob Falter.......

[cywelchjr]

If you richen your mixture it will run cooler if there is an overheating problem. Alcohol does burn much cleaner and more efficiently. Drag racers and dirt track racers run a very rich ethenol fuel mixture. Rich to keep the engine cool ethenol because it increases horsepower.

The problem with ethanol is that it's very corrosive and damages the fuel system components of older vehicles that are not designed for it. It also attracts water and will cause the inside of the tank to rust as well, which is why many newer tanks are lined to prevent this. It does however burn clean, but it also has much less energy per gallon than gasoline so you will go less distance per tank as well.

[HobbyMan]

Ahh the old fuel question. One for the books. Or lots of books for that matter.

If you ask me, which you probably won't because I could give an earful, or eyeful for that matter, this is what I would say:

Personally, we don't have much of a say as to what we but in our tanks. Ethanol, non ethanol, the whole debate sucks. Higher or lower octane makes zero difference but you can argue it all day long. When it comes to a road trip, are you going to be able to find a non ethanol (preferred) gas station? Probably not.

However what does matter to me is how often I have to clean my carbs and replace the fuel lines. I have heard a few people say that modern gasoline doesn't go bad. Well, from several personal and recent experiences, gasoline just doesn't last that long (a few months). This is why when I park the bike for more than a week, I fill up with 100LL. Going to 100 octane, you can actually feel a difference (well I think I can). After running 3 or 4 consective tanks of 100 low lead and then going back to regular car gas, there is definitaly a change. Is it good or bad? I have no idea. However, I can tell you that running aviation gasoline keeps everything very clean. The FAA does not let the epa put half of the environmental chemicals in there. Some times I run 100LL that has been sitting in cans for several years and it is just as fresh as the day it was made.

So far the only consequence to running 100 low lead avgas is the fact that I should pull the plugs about every 5k miles to give them a light wire brushing. I know the obvious side effects of breathing leaded exhaust, or plain exhaust for that matter but when you do smell it, damn it does smell good. One final thing is that it is at least a 1$ more expensive than regular car gas but when you know the right people and get it for free on occasion, the price is not an issue.

If you are going to let your bike sit for a period of time, 1+ months, I highly suggest run a tank of 100LL and then fill it up to the top.

I am the 1.23%

[WMarshy]

I see the local station now has 91 non ethanol fuel. Im going to give it a try, I just hope its not already stale as I think the majority of their sales are from the snowmobilers during winter...

[skipper]

My son took over my performance shop some years back. His main income comes from setting up race car computers. His chassis dyno can read fuel consumption quite closely. A test a few years ago showed an average drop in MPG of 9% using 10% ethanol fuel over straight gas (17 cars tested). One vehicle (Honda hybrid) a whopping 24% drop in mileage! We live in Florida, it's wet here, alcohol is hygroscopic, HELLO!!!! We need to stop this insanity.