I ride a 05 and was first panicking about the difference in fuel consumption. I ride fast and 32-35 is total normal. I agree with some of the colleagues here saying, that the difference is made by over/under 3000 rpm riding. It’s a 6 cylinder and they need to be fed ? Enjoy your new bike...it’s a great feeling! Ride safe!

 

Chilly but still got out for a bit today to check the speedo error and run some magic juice through it. Speedo is 80 when GPS says 76. So the 5% deviation is exactly the same as my GL1000's. I did not get a chance to check the odometer but suspect it will be off about the same. 70 MPH indicated on the speedo is just a needles width below 3,000 rpm, there it was bouncing between 66 and 67 on the GPS. She gets to 110 (indicated) pretty good but seems to flatten out there. I was pushing it pretty hard today so no sense in checking this tanks mpg.



O2 Sensors finally shipped but do not expect them before Monday or Tuesday.



Oh and I am short but not little :laugh::laugh::laugh:



Bolt kit arrived for the Ram exhaust manifold so I can break out the welder and spend some time working on that in the mean time.

 

I have an 012 and get 35-37 and I ride hard, so you are right where you should be.

 

I just checked my 2013 recently and it was 44 mpg. It is always around that when I check it.

Stock bike with stock windshield with the exception of a car tire.
I ride easy.... usually 65mph or less.
I waste my money on mid grade gas from chevron or shell.
Bike is fitted with a Yoko RF tire CT in the rear at 30psi and a Dunlop E4 in the front.

 

I have an 02 and I get a steady 43mpg. I drive easy most of the time, but do hot rod some everytime I get it out. When carrying a passenger and pulling a loaded trailer, I will get around 32mpg.

 

First thing first. Welcome to the big 6 world. You went from 1 big bike to now having 2 big bikes between your legs.


On my 95, I got 36-38 consistent and yes the speed on odometer were both off about 5-6%. That was consistent for the 65K I put on the bike. My 2010 ticked that up by one. I normally get 37-39 but have only put 10K so far (I normally put on 17K a year primarily commuting in the Dallas area). I was surprised my mileage did not drop when I when to the BB&Q in Fayetteville AR last year. It was cool but I was also pushing it more than what I normally do. OH YA the corner speed governor did limit me to a reasonable +10-15 over the PSL but without the governor riding I was doing +20-25. This is all on the 87.


On my 95, I would add 1 oz of 2 cycle gas oil to a fuel tank of gas and get another 1-1.5 miles per gallon.


Enjoy the ride and keep reading and asking questions as you learn what you and your bike can do.

 

300 miles today. First tank was a load of seafoam and I was not gentle so I did not check it for economy. Second tank full was easy country roads using the cruise a lot. Rode like grandma was on the back. I got 37.2 mpg. So some improvement.



Got home and the O2 sensors were finally delivered so they will go in tomorrow. Looks like a couple more nice riding days toward the end of the week.



I don't know why, but I am starting to "suspect" the aftermarket exhaust is part of the issue. Low end torque is super strong on this and I do not remember it being that dramatic on the other 1800's I have ridden. Just thinking out loud now.

 

New O2 sensors installed today. Try to get out tomorrow for a run to see if they have any effect.

 

Got out for 350 miles today. On the way out I was running into a steady 15-20 mph headwind. On that tank I got 36.9 mpg. On the way back (tail wind but not as strong) according to the gas gauge I did a fair amount better but I have not filled it yet to know for sure what the number is. I know for the first time I saw 125 miles on the trip meter at half a tank so optimistic that there is some improvement.

 

O2 sensors can wear, and sometime changing them will help if they have a lot of miles on them. I'd also change the spark plugs, and make sure to install the proper NGK plug.

Also, you don't say where you are from, but if you ride out west a lot with higher speed limits don't expect much over 36mpg. Also, if you have a larger windshield or air wings installed it will decrease mileage.


Personally, I would never expect to see over 38mpg in normal use on a GL1800. You'll obviously get better mileage at altitude, but under normal conditions, 36 - 38 MPG is what I would consider normal.

 

Sea level. Norfolk Va Yes I have a full set of wind wings and a F4 tall windscreen. Plugs are new FSM spec NGK's. Also has a Vance and Hines Monster exhaust.

 

Your mpg seems to be in the ballpark of most other 08 owners.
Yes your aftermarket pipes are very likely causing you to loose some horsepower and mpg but the extra noise makes you feel it has more power.
The extra big windshield and wind wings are also costing mpg.

I rode with a guy once that called me a liar when I told him I was averaging 43 mpg, so we both filled up at the same place and refilled about 175 miles later, he got about 5 mpg less than I did, he claimed he was riding way faster than me but the fact is he had been riding within 1/4 mile behind me all the while, I believe he just has very mpg unfriendly driving habits.

 

It`s nice to know your MPG, but I never thought it was so important to that many people. My take is if you want to ride you have to buy gas, so don`t worry about it.

 

Two full tanks today on the slab cruise locked at 80 mph indicated (76 on the GPS) resulted in 34.0 and 34.2

 

Right on the money.

Dial it below 3000 rpm, and you'll get another 1 maybe 2 MPG's.

 

My 2005 experienced a drop in fuel economy at one point.
After checking a lot of things and discussing with many people, I think it was Fred Harmon that finally suggested that I check the fuel pressure regulator. Instead I just replaced it and my fuel economy came back up.

BTW, I would regularly get 38 to 40 mpg on my daily boring drive to and from work. When the regulator failed it dropped to the mid to high 20's

 

Is a special tool required, to remove the Oxygen Sensors?


I ask because Harbor Freight sells a couple versions of this:
( https://www.harborfreight.com/3-8-eighth-inch-offset-oxygen-sensor-wrench-97177.html )

 

No special tools. Pretty sure I used a 7/8" comb wrench.

 

A few days ago I ran down to Orlando. Solid 34 mpg on the slab. While there I swapped to the colder 7 plugs. Gained exactly 1 mpg. Now at 35 locked at 80 mph indicated

 

I ride it like I stole it and my 05 Wing averages around 35 mpg. Revs to 5k + regularly, see speedo reading over 120 regularly, cruise on hwy between 85-90+ still 35.

If I ride slow and easy, mpg only improves a little. Never seen 40 mpg.

 

When the bike was new, I figured the data once... recall it was 38 mpg or so, that was over ten years ago. Check it at high altitude riding in CO once, got about 45 as I recall. I've never calculated it since.

 

Just to close this out. Last week I returned from a 7,200 mile run from Virginia to Oregon and back. I saw anything from 31 mpg up 39 mpg. When I figured out the entire route I came up with an average of 36 mpg using GPS mileage and actual gallons pumped. I did not track all the variables but I do know my worst days I was fighting a head wind. The over sized windscreen and wind wings are certainly a large part of the issue for this bike. I have faith that the bike is running as it should and am accepting this as it's normal.


Thanks for listening to me vent on the issue!!