That sounds suspiciously like the gas flow meter at the garage where you got lower mileage (higher consumption) has been 'altered' to over-read.....????
Worth looking into........

 

I use seafoam in my gas because it has been highly recommended by so many people.

 

The pumps are dead on...i thought the same thing so i bought a gallon in a gas can to use in the lawnmower. They may be adding ethanol though, that burns less efficently than full petrolium gasoline.

 

There is no need to run high octane in our bikes. the ONLY thing it will do is slow down flame burn and on a low compression engine (like ours) it will not give the same punch per stroke as a lower octane with a faster flame travel. You need to pump more fuel into the combustion chamber to acheive the same amout of power with a higher octane.

I repeat... there is no extra or hidden power in a higher octane gas.

Put the low octane stuff back in and I bet the mileage goes up.
FWIW I get a consistant 39 commuting (about 50/50 city highway) and 45+ solid highway or non city. I can go right around 200 miles on a tank loaded and touring, even in the twisties. I have never put in anything other then the low 87 octane.

One last thing. Make sure that you aren't using the E-85 crap. That's too much ethonal and will kill mileage too. About 10% is the max for our bikes and that's about all they put in the gas around here. If you have higher ratios then 10% try using some Stabil for marine engines. It helps counteract the negative effects of high ethonal.

 

Great Thread guys! I have been putting hi test in for a while as it felt like my bike pulled stronger in 8000rpm range than regular. I've been averaging 37mpg. Now you guys have got me thinking. Back to regular I go. Thanks!

 

I am currently in Grandbury,TX. Some of the gas here has 15% ethanol. Ethanol, as just stated, kills MPG (KPL). My rental car shutters at stops with 15%E and runs smooth with regular gas.

Not only does the bike use more gas, it will have less power and run hotter. Look at the pumps that you are filling up at. The ones that are producing poor economy are most likely laced with ethanol.

 

Nice. Thanks for the info. I will give it a try.

 

I can only echo what everyone has said about the ethanol gas. It not only sucks, but it will clog everything up.

Around town I also get around 35ish MPG. Touring at around 80mph i get around 45-50MPG.

 

So, this means that you can switch from an Ethanol based to a non-ethanol just like that, no changes in carburation nor anything?? better be prepared since these will be unfortunately the gasolines of the nearfuture.

 

These are not ethanol based (at least in the US) they are just using ethanol as a "filler" or additive. That is why it has less than 10 or20% ethanol. E-85 is ethanol based (85%ethanol 15% gasoline) and to start burning E-85 we would need to make major changes in carb jettingand replace seals and fuel lines as ethanol tends to degrade normal fuel lines.Not to open a can of worms but there is no way the US let alone the world could ever start using E-85 instead of gasoline. For corn ethanol to completely displace gasoline consumption in this country, we would need to appropriate all U.S. cropland, turn it completely over to corn-ethanol production, and then find 20 percent more land for cultivation on top of that.

Back to the topic of mileage though, it appears that some companies have started using a 20% blend instead of the 10% blend they were using. That would appear to be the culprit in this case.