Getting Poor MPG GL1800

[Can Do EOC]

Fellow Riders,

Looking for some help, I have noticed lately that I am not getting the proper MPG on a full tank of gas. I drive to work daily which is a 20 mile round trip average speed would be 60mph, I filled up the bike and normally I would get about 220 before the next fill up, well now barely 150. I have 75,150 on the girl, what could be causing this to happen.

[harvey01]

Do you get a winter blend of gas there? But that should only cause a couple MPGs.

When was the last time the spark plugs were replaced? When was the last time the air filter was replaced? When were the valves last adjusted? What tire pressures are you running? Have you had the O2 sensor checked?

Hopefully others will chime in with more ideas or questions.

[NVSB4]

I'm really glad that you are comparing past mpg to current on your bike instead of asking about what others might get. That opens up a whole other can of worms.
You are right to think that something might be wrong if suddenly the mpg drops.
Has anything changed prior to the drop? Was this for just one tank, or several?
As Harvey said, there are a lot of mechanical / maintenance things to check.

[Viking]

there are a lot of mechanical / maintenance things to check.

All of the above, plus riding style. Have you been ripping the throttle a bit, as I find that eats fuel in these bikes. Another thing is cold weather running. Are you having to allow the bike more time at start up, in order for the revs to come down? It is on choke at this time, and that eats more fuel. That is a big drop in mileage, and the first thing I would be thinking about would be the Air Filter, if you have no MIL lights coming on. How many miles since the Air filter has been changed, if it has ever been changed. Many GL1800s under 80K miles often have not had this done due to the onerous task that it is.

[thrasherg]

If the bike is running well, I doubt much has changed, probably a change in fuel or riding style. I have over 25K miles on my GL1800 and always have the low fuel light come on between 160 & 170 miles!! Must be the way I ride!! Let us know if you do find anything as maybe I have the same issue without realizing it..

Gary

[Wingsconsin]

Using the miles to fill up method is a poor excuse for finding out MPG in my opinion.

IF you are going to track MPG (a good idea for this reason) then knowing what the actual MPG IS would be helpful.
Do the math -- Miles Per Gallon -- how many gallons have you been buying and how far does that take you....

That being said it is common as the fuel changes from the factory to a 'winter blend' - poor MPG is a symptom of winter blend fuel, longer warm up times, and more dense air all contributing to changes in fuel economy.

If this problem persists in Spring once it is warm again I would worry...But DO take a look at your maintenance schedule and see what has been forgotten -- air filters, plugs, even a hanging brake could affect MPG dramatically.

Good Luck