Poor Gas Mileage???


Information and questions on GL1500 Goldwings (1988-2000)
Post Reply
User avatar
zeoran
Posts: 134
Joined: Wed Apr 17, 2019 12:11 am
Location: Redondo Beach, CA United States
Motorcycle: 1999 GL1500A, 2002 Honda ST1100, 1982 Honda Interstate (sold)

Poor Gas Mileage???

Post by zeoran »



I have a 99' Aspencade, bought in March of this year with 67k miles on it. I've replaced the fuel filter, air filter, checked the oil, done all routine maintenance and made plenty of upgrades/etc. I use it primarily to get to/from work every day, which is a 100 mile commute. I've noticed that I'm only getting about 170 miles/tank which works out to only 29mpg. My 2002 ST1100 got around 42mpg. I expected it to be lower than my ST1100 but 29mpg seems too low. What could be causing the lower gas mileage?

God bless,

~Mark



User avatar
blupupher
Posts: 162
Joined: Sun May 17, 2020 5:47 pm
Location: Katy, Republic of Texas
Motorcycle: 1994 GL1500 SE

Re: Poor Gas Mileage???

Post by blupupher »

Are you using actual gallons used and exact number of miles?

I have gone 162 miles on "a tank" (4.86 gallons, 33.33 mpg) and 170 miles on "a tank" (4.17 gallons, 41.75 mpg).

There are so many variables in MPG on a bike, road conditions, wind, traffic, hills, how much you like the throttle etc.
My 41 mpg trip was a tank with me doing ~65mph for most of the tank, my average mpg is closer to 30, since most of my riding is a short to and from work with a longer ride about once a week on the same tank. I have had as low as 24 mpg with only short trips.
1994 GL1500 Goldwing SE

User avatar
zeoran
Posts: 134
Joined: Wed Apr 17, 2019 12:11 am
Location: Redondo Beach, CA United States
Motorcycle: 1999 GL1500A, 2002 Honda ST1100, 1982 Honda Interstate (sold)

Re: Poor Gas Mileage???

Post by zeoran »

I'm using an exact number of gallons and exact miles. It varies +- 2-5 miles.
I fill up at Costco and I fill up to the top every time so I know I'm getting the exact same amount of gas each time. Last time I got 160 miles on 5.5 gallons.
I don't accelerate hard and I can't brake hard. Since the lockdown, traffic is non-existent and I use the cruise control to maintain 75mph each way to/from. The amount of wind varies on the day, so does heat. (t's been hot here in Southern CA lately) But it's been like this for a while.

Just seems like 29mpg is a bit low, even for a Goldwing.

User avatar
wingdings
Posts: 490
Joined: Mon Feb 10, 2014 12:48 pm
Location: mells , England, United Kingdom
Motorcycle: Honda Goldwing gl 1989

Re: Poor Gas Mileage???

Post by wingdings »

Hi - Saw your post there !! - Have you checked the following -

Air filter - is black and ready for changing ?? - if the engine cannot breath - you will get crap mileage

Spark plugs ?? - are correct gap in good order too ?? -

oil - what grade is it ?? - When was it last changed ?? .

Brakes are they binding ?? - Rear ones are prone to do this ..

Another common cause of bad mileage too - that if the timing belt has slipped a tooth and thrown the whole lot out of wack that will cause bad mileage too !!.

Lastly - How much weight are you carrying around on the bike - The more stuff you carry about - the more fuel you will burn and use too ..

Hope this helps :D :D :D :D

User avatar
zeoran
Posts: 134
Joined: Wed Apr 17, 2019 12:11 am
Location: Redondo Beach, CA United States
Motorcycle: 1999 GL1500A, 2002 Honda ST1100, 1982 Honda Interstate (sold)

Re: Poor Gas Mileage???

Post by zeoran »

Air filter - is black and ready for changing ?? - Recently 'recharged'. High end filter. The fuel filter is brand new, recently replaced.

Spark plugs ?? - are correct gap in good order too ?? - Haven't checked the plugs, but she runs/sounds perfect.

oil - what grade is it ?? - When was it last changed ?? . I don't remember the exact brand, the previous owner changed it right before he sold it to me in February/March of this year.

Brakes are they binding ?? - Rear ones are prone to do this .. I don't think they're binding. In fact, I've been having a big problem with the lack of stopping power. I've bled the brakes...twice. (front and rear) with 5.1 fluid. And I JUST got through replacing the front brake cable with a new steel-braided cable. It's helped some but I think I need to change out the stock/oem pads with the EBC pads and do a rebuild on the calipers to truly get the stopping power I'm looking for.

Another common cause of bad mileage too - that if the timing belt has slipped a tooth and thrown the whole lot out of wack that will cause bad mileage too !!. I'm fairly certain that the timing belt is ok. Again, she runs great and sounds perfect. I've put over 3k miles on her in just the 5 months I've owned her.

Lastly - How much weight are you carrying around on the bike - The more stuff you carry about - the more fuel you will burn and use too .. Umm... there you have me. I'm 320lbs myself and I have a LOT of stuff in the saddlebags. (I like to be over-prepared) Thing is, nothing I'm storing is necessarily 'heavy' except myself and I was the same weight when I was riding my ST1100 and it got over 40mpg.

User avatar
blupupher
Posts: 162
Joined: Sun May 17, 2020 5:47 pm
Location: Katy, Republic of Texas
Motorcycle: 1994 GL1500 SE

Re: Poor Gas Mileage???

Post by blupupher »

zeoran wrote:
Mon Aug 17, 2020 12:27 pm
I'm using an exact number of gallons and exact miles. It varies +- 2-5 miles.
I fill up at Costco and I fill up to the top every time so I know I'm getting the exact same amount of gas each time. Last time I got 160 miles on 5.5 gallons.
I don't accelerate hard and I can't brake hard. Since the lockdown, traffic is non-existent and I use the cruise control to maintain 75mph each way to/from. The amount of wind varies on the day, so does heat. (t's been hot here in Southern CA lately) But it's been like this for a while.

Just seems like 29mpg is a bit low, even for a Goldwing.
Drop your speed to 65 MPH for a tank and see how it does.
When you get above 3000 rpms, it really starts drinking the gas.
1994 GL1500 Goldwing SE

User avatar
AZgl1800
Posts: 2453
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800
2009 Piaggio MP3 250cc

Re: Poor Gas Mileage???

Post by AZgl1800 »

blupupher wrote:
Mon Aug 17, 2020 3:29 pm
.
Drop your speed to 65 MPH for a tank and see how it does.
When you get above 3000 rpms, it really starts drinking the gas.
[/quote]

That is for sure, I have an old spreadsheet that I post when this subject comes up.
It very religiously recorded every drop of fuel for a year, this one portion of it only covers about 5,000 miles.

but look at the MPG and the associated Description of the Conditions on the one tank of fuel..
22 mpg to 45 mpg is a lot of territory, depends on every thing, big windshields ( Tulsa Tall on the bike here ), throttle control, wind, terrain...



~John

'02 GL1800
2009 Piaggio MP3 250cc

User avatar
zeoran
Posts: 134
Joined: Wed Apr 17, 2019 12:11 am
Location: Redondo Beach, CA United States
Motorcycle: 1999 GL1500A, 2002 Honda ST1100, 1982 Honda Interstate (sold)

Re: Poor Gas Mileage???

Post by zeoran »

Interesting spreadsheet...you seemed to maintain mid-30's even doing 95mph on most occasions and only dropped to low 20's during high winds.

The windshield on my 99' isn't stock but it's not as tall as I'd prefer either. I had a 24" on my ST1100 to get it so it went above the top of my helmet. This windshield is a couple inches shy and I can feel the wind push down on my head when I get up to freeway speed (75mph).

I just filled up again this morning and it usually goes through 1/2 tank every day so I'll wait till I fill up again on Wednesday morning to try the 65mph trick. That's going to make a long trip even longer but it's just to experiment.

I know that wind does play a big role... when it first started getting hot, I started going home with the vent open and that really killed my fuel efficiency.

Does anyone know about air shock setting/tire pressure having an effect? I usually keep the rear shock at around 36psi and the tires are at 42/46. But this heat is likely affecting the tire pressure as well.

User avatar
AZgl1800
Posts: 2453
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800
2009 Piaggio MP3 250cc

Re: Poor Gas Mileage???

Post by AZgl1800 »

If anyone should want that Spreadsheet,

I would pass it along via your email....

I would blank out my info you could insert yours.
~John

'02 GL1800
2009 Piaggio MP3 250cc

User avatar
ct1500
Posts: 1425
Joined: Wed Nov 10, 2010 8:09 pm
Location: Glastonbury,CT
Motorcycle: 1988 GL1500
Contact:

Re: Poor Gas Mileage???

Post by ct1500 »

zeoran wrote:
Mon Aug 17, 2020 2:49 pm
Spark plugs ?? - are correct gap in good order too ?? - Haven't checked the plugs, but she runs/sounds perfect.
"But it runs and sounds perfect" :)
Is a common denominator when folks come to the Forum wondering why their mileage or performance is not as good as others. Until you have ridden a correctly tuned and running 1500 which should be able to stand a dime on end atop the engine, you don't know for sure if it is indeed running/sounding perfect. :?: You have to look for the causes.
Do not let anyone try to convince you poor fuel mileage is normal on a 1500 if properly ridden, maintained and repaired. :roll:
viewtopic.php?f=6&t=55606
Local and need repair help with your 1500, Valkyrie or ST please click contact
Nothing leaves my shop till its' perfect
This is what I do

FM-USA
Posts: 2848
Joined: Wed May 18, 2011 8:40 am
Location: here, there, WHY?
Motorcycle: mc's

Re: Poor Gas Mileage???

Post by FM-USA »

My experience of "What could be causing the lower gas mileage?" was vacuum leaks. The unseeable PIN-HOLE type.
Had to stretch the hose to open them critters up. Also, when I had to change my 2 chrome coolant tubes O-Rings (from thermostat housing to both heads) I found the 2 carb boots were loose, rubber boots must have shrank over the years.
MAYBE your issue? :roll:


I'm hounded for posting helpful solutions? ARGO!!! (2012 film)
"Let's see how long this round will last."

Post Reply