Fuel Mileage


Information and questions on GL1500 Goldwings (1988-2000)
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GBKid
Posts: 100
Joined: Fri Jul 03, 2015 9:54 pm
Location: Oostburg, WI
Motorcycle: 2000 GL1500 SE 25 Year Anniversary Edition

Fuel Mileage

Post by GBKid »



I own a 2000 GL1500 SE (25Year Anniversary Edition) and I was wondering if anyone knows to what degree (pun intended) the air temperature normally impacts fuel mileage. I have noticed that when the air temperature drops below 55 degrees the fuel mileage decreases anywhere from 3-6 mpg and is the least efficient when it coldest, particularly when traveling at Interstate speeds of 70 mph or more. In warm weather the mpg is typically 36-40 mpg with the lowest mpg again at Interstate speeds of 70 mph or more. I did install a new air filter, fuel filter, sub filter, and spark plugs about 3 months ago FYI. The bike has 61,000 miles on it and is in excellent condition.



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DenverWinger
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1980 GL1100 STD Vetter (2005-)
1993 GL1500 Aspencade (2017-)
1983 Trav-Lite Camper (2010-)
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1972 CL350 (1980-1988) sold
1978 Suzuki GS550 (1985-2005) sold
1977 GL1000 (2002-2006) sold

Re: Fuel Mileage

Post by DenverWinger »

I haven't really noted any difference in fuel use in colder weather.... It's possible your thermostat is stuck open not allowing the engine to warm to normal operating temperature.

Once warmed up, even in cold weather, you should see the temp gauge reach at least 1/4 scale, and it should reach that fairly quickly (just a few miles). There's coolant lines running thru the fuel system warming the carbs and manifolds, once warmed up the ambient temperature shouldn't make much difference.

If you are getting a 1/4 scale reading in a reasonably short time your thermostat is probably OK.
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GBKid
Posts: 100
Joined: Fri Jul 03, 2015 9:54 pm
Location: Oostburg, WI
Motorcycle: 2000 GL1500 SE 25 Year Anniversary Edition

Re: Fuel Mileage

Post by GBKid »

Thank you! I believe you solved my problem because 2 days ago the temperature was 40 degrees and the temperature gauge needle did not rise above the 1/8 mark and took forever to get there. Time for a new thermostat!

GBKid
Posts: 100
Joined: Fri Jul 03, 2015 9:54 pm
Location: Oostburg, WI
Motorcycle: 2000 GL1500 SE 25 Year Anniversary Edition

Re: Fuel Mileage

Post by GBKid »

On second thought, I’ll leave well enough alone after seeing what it entails to replace it. The bike will be going into winter storage soon and the additional fuel consumption costs because of the lower mpg is worth it to avoid that project. I don’t ride too often when it’s really cold anyway.

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WingAdmin
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Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
2012 Suzuki Burgman 400 (wife's!)
2007 Aspen Sentry Trailer

Re: Fuel Mileage

Post by WingAdmin »

Cold air is much more dense than warm air, which means wind resistance as you ride increases. Wind resistance (drag) increases as a square of the velocity, so the faster you go, the more the cold air will kill your mileage. Wind resistance is the "aerodynamic" line shown in the chart below:




GBKid
Posts: 100
Joined: Fri Jul 03, 2015 9:54 pm
Location: Oostburg, WI
Motorcycle: 2000 GL1500 SE 25 Year Anniversary Edition

Re: Fuel Mileage

Post by GBKid »

Thank you WingAdmin. Also thank you for this great site and all of the WingNuts like me who contribute to the forum. My 2000 GL1500 SE is my second Goldwing in 4 years. My first one was a 1989 GL1500 I restored using the How To articles and Goldwing Chat and Tech Talk posts. That bike was wrecked a year ago on September 13th after my brother and I got hit from behind by a car getting pursued by the police. We were out of state on the first day of a 10 day trip that was going to take us to Nashville and the Blue Ridge Mountain Parkway among other places. We were both seriously injured, but we both had helmets and protective gear on that saved our lives. Initially, I was not going to buy another bike ever again, but as I got better I kept receiving your monthly newsletters, which I always enjoyed, and those newsletters made me realize how much I enjoyed riding and the Art of Motorcycle Maintenance so to speak (I read Zen and the Art of Motorcycle Maintenance years ago and highly recommend for you and your readers). Therefore, I bought my current 2000 GL1500 SE (25 Year Anniversary Edition) in May after looking at several GL1800’s first and I’m back in the saddle again. I really like the GL1500 for a lot of different reasons and this site is a big help to maintain them. Thank you again and Happy Trails to you and all of us Wingnuts that are members.

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C-dub
Posts: 537
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1979 Suzuki GS850G
1983 Suzuki GS1100E
1981 Honda XL250
1975 Suzuki GT185M
1970 Suzuki TC90 dirtbike

Re: Fuel Mileage

Post by C-dub »

There's also the issue of horsepower related to air temperature and humidity. Since colder air is more dense there is also more molecules, which means more energy released. The drier the better since we all know moisture in the form of water isn't good for combustion. So, there's bound to be some beneficial effect of increased hp on mileage. I don't know if it will be as much as the negative effect of air density on drag, but more hp should mean the engine doesn't have to work as hard to get to or maintain speed thus increasing mpg some.
I am not and have never been a LEO. My avatar is in honor of my friend, Dallas Police Sargent Michael Smith, who was murdered along with four other officers in Dallas on 7.7.2016.

GBKid
Posts: 100
Joined: Fri Jul 03, 2015 9:54 pm
Location: Oostburg, WI
Motorcycle: 2000 GL1500 SE 25 Year Anniversary Edition

Re: Fuel Mileage

Post by GBKid »

In a car you're always in a compartment, and because you're used to it you don't realize that through that car window everything you see is just more TV. You're a passive observer and it is all moving by you boringly in a frame.

On a cycle the frame is gone. You're completely in contact with it all. You're in the scene, not just watching it anymore, and the sense of presence is overwhelming.
Robert M. Pirsig, Zen and the Art of Motorcycle Maintenance: An Inquiry Into Values

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newday777
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Location: Milford NH summer/fall & Oceanside, CA winters(N San Diego) with lots of miles riden between
Motorcycle: 2008 Cabernet Red. Level 4

1983 GL1100A Wineberry 36,000 miles

1975 CB750 K5 Planet Blue 7,800 miles

1976 CB750 K6 Anterris Red 25,000 miles

Past rides
1999A Restored from PO neglect & sold at 19,000 miles

1999SE Totaled by cager at 105,000 miles

Re: Fuel Mileage

Post by newday777 »

Don't forget the effect of winter blended ethanol will have dropping fuel mileage :evil:



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