Poor Fuel Mileage

[ultrafxr]

Just returned from a fantastic eight day trip to the Texas hill country. Well it was fantastic except for that brutal cold snap that came in last weekend. Thank goodness for heated jacket liner, seat and grips.

Anyway just wondering why I am getting such poor mileage on my 2018 Tri-Glide. Friend rode with us and we are both on 2018 Tri-Glides - mine bought last September and his just last month. Both TGs are bone stock - no mods other than shocks on mine and lift kit on his.

Both of us were riding two up with about the same amount of luggage and rider /passenger weight not much different. But he consistently got about 34 to 35 mpg while I only got about 30 mpg (and on a couple fill ups it was just a tad over 29 mpg). We rode very, very little interstate - mostly two and four lane state and county roads with speeds around 60 to 65 mph. It was windy and we fought head winds quite a bit. But still the two bikes were very far apart on fuel mileage.

Just wondering if anyone had thoughts about what to check.

[MDO]

Being under warranty, why not have a friendly conversation with the dealer you purchased it from, and explain the situation.

[frostbite51]

Drive in a lot of dusty days? A partially clogged air filter will hit your MPG.

[ultrafxr]

Being under warranty, why not have a friendly conversation with the dealer you purchased it from, and explain the situation.

Thanks. Plan to do that but hope to get some ideas before I do.

[ultrafxr]

Drive in a lot of dusty days? A partially clogged air filter will hit your MPG.

Good thought but no. Bike had only 2,900 miles when I left and I did check the air filter beforehand and it was spotless. No dusty areas on the trip. May clean the air filter just because even though it looks clean.

[Burnerboy]

Just a thought, is your windshield bigger then his??

Ronnie

[GARYD]

I ride solo usually over the speed limit. I don't baby my 14 TG at all. I average 32 to 35 mpg. I carry in the trunk, rain gear, tools, tire repair kit plus other odds and ends - all the time and still get that mileage. Would I like 40mpg? Sure, but I'm not going to sacrifice having fun and drive like a little old lady.

I would think if you're riding 2 up with luggage and riding into the wind, 30 mpg seems about normal.

I don't let mpg bother me. I can ride the same route one week and the next it will be different - the 3rd week even more different.

I've been recording my mpg on my bike and cars for many years, ever since I had to do that in the Marines.

You have different temps, different tire pressures, different weights, different wind speeds different riding habits (fast starts etc) brakes dragging, and so on. Unless it's scientifically controlled, I don't know how anyone can accurately tell why they get different mpg figures from bike to bike or day to day.

Next time you bring your bike in for service, mention it. Maybe you do have something going on.

Good luck

[Sully]

Too many variables to compare Trike to Trike. When I'm running 65 mph or more I put it in 6th gear. Roll the throttle lightly and maintain your speed. No reeving it up and down. 30 to 35 is good for a Trike.

[Bikerbozo]

If the trikes were both bought from different dealerships, it might be a case of different tuning programs to account for lean emissions crap HD sends out from factory.

[ultrafxr]

If the trikes were both bought from different dealerships, it might be a case of different tuning programs to account for lean emissions crap HD sends out from factory.

Same dealership but they did have to bring mine in from another dealer in KY. Mine was made in September and his in February so maybe there has been an updated calibration his trike has. I'll check on that.

[DK Custom Products]

Just returned from a fantastic eight day trip to the Texas hill country. Well it was fantastic except for that brutal cold snap that came in last weekend. Thank goodness for heated jacket liner, seat and grips.

Anyway just wondering why I am getting such poor mileage on my 2018 Tri-Glide. Friend rode with us and we are both on 2018 Tri-Glides - mine bought last September and his just last month. Both TGs are bone stock - no mods other than shocks on mine and lift kit on his.

Both of us were riding two up with about the same amount of luggage and rider /passenger weight not much different. But he consistently got about 34 to 35 mpg while I only got about 30 mpg (and on a couple fill ups it was just a tad over 29 mpg). We rode very, very little interstate - mostly two and four lane state and county roads with speeds around 60 to 65 mph. It was windy and we fought head winds quite a bit. But still the two bikes were very far apart on fuel mileage.

Just wondering if anyone had thoughts about what to check.

Interesting...both of you traveling the same road, the same time, the same speed on the "same" trikes. Even a weight difference (if there was any) of as much a 100 lbs will not make a perceptible MPG change. Seems like there are only two variables-

1. Riding style (twist of the throttle and what gear you both were running...RPM's)

2. Something IS different between the Trikes.

btw, the M8's do get better MPG than the Twin Cams, and 34-35 (and even a bit higher) mpg for that kind of riding is reasonable to expect.

So, for you to be getting 30 mpg, either your RPM's were significantly different than his, or there is something amiss with the TG. The list is endless, but I would start with the following, to try and narrow it down:

1. Brake dragging

2. Something else dragging, like bearing or overly tight belt

3. Spark plug or Plug wire bad

4. Tune bad

5. O2 sensor or connector bad

6. Intake or exhaust leak messing with the AFR

7. Super low tire pressure...like well below 20 psi in the rear to cause that much of a loss in mpg ( don't know that that could even make that much difference)

That is off the top of my head...there may be some other minor things I am not thinking of right now.

Kevin

[ultrafxr]

Interesting...both of you traveling the same road, the same time, the same speed on the "same" trikes. Even a weight difference (if there was any) of as much a 100 lbs will not make a perceptible MPG change. Seems like there are only two variables-

1. Riding style (twist of the throttle and what gear you both were running...RPM's)

2. Something IS different between the Trikes.

btw, the M8's do get better MPG than the Twin Cams, and 34-35 (and even a bit higher) mpg for that kind of riding is reasonable to expect.

So, for you to be getting 30 mpg, either your RPM's were significantly different than his, or there is something amiss with the TG. The list is endless, but I would start with the following, to try and narrow it down:

1. Brake dragging

2. Something else dragging, like bearing or overly tight belt

3. Spark plug or Plug wire bad

4. Tune bad

5. O2 sensor or connector bad

6. Intake or exhaust leak messing with the AFR

7. Super low tire pressure...like well below 20 psi in the rear to cause that much of a loss in mpg ( don't know that that could even make that much difference)

That is off the top of my head...there may be some other minor things I am not thinking of right now.

Kevin

Thanks a bunch Kevin. All great ideas. In thinking about them here is what I came up with.

Doubt the weight difference between our two rigs was over 50 pounds. We were both two up and loaded for the very same trip and carried about the same amount of luggage.

Riding style - I do twist it a bit more . . . but just a bit. We were riding together and staying together but I was in the lead and got to highway speed just a tad bit quicker - but nothing that should make 10-15% difference in fuel mileage. Most riding was 55 to 65 mph and most of the time I was in 6th gear. Assume he was too but I'll verify.

Jacked it up and checked all three wheels. No brake drag that I can discern. Bearing that bad should made noise and I / we heard nothing. Drive belt is tight but so is his. Tech said moco likes to get them tight during assembly as they will loosen a bit. My bike started the trip with 3,000 on the clock. His with 800.

Spark plug or plug wire. Would think it would throw a DTC but checked (several times) and nothing. Bike ran just great.

O2 sensor bad or bad connection. Again would expect a DTC and poor performance.

Intake or exhaust leak. Might not throw a DTC but have experienced both and they affect idle especially - speed variation and even stalling. Nothing like that at all.

Tire pressure - I was running 22 and he was running 23.

Service manager at local dealer is on vacation but I am going to check with him next week. Perhaps there is an updated calibration his trike has being several months newer.

Not all that concerned except for the fact that they were so different. And I don't like having to stop for fuel so often. Range indicator hardly showed 180 miles with a full tank!

[FuzzyWuzHe]

I have a friend who gets about 20% less mpg on his Ultra than I do on my Limited. He sits at a light and rolls the throttle several times, he likes the rumble. It's amazing how much that affects his mpg's, he claims to not care, but on a recent burger run, he spend 5$ more on gas for a 200 mile round trip. We filled when we got there and when we got back. I have him by about 100# and I carry about 40-50# of tools at all times. The big difference, he likes the zroooom zroooom sound .. LOL. Me too, but, not enough to spend $5 extra dollars on every 200 miles ...

[rhino 2]

t

Not all that concerned except for the fact that they were so different. And I don't like having to stop for fuel so often. Range indicator hardly showed 180 miles with a full tank!

Then it could be you aren't filling the tank ''right'' to the top.....When i fill my 17 T/G The range indicator will show 220 miles to empty , With my 11 T/G 205.... ..

[Jack Klarich]

If the trikes were both bought from different dealerships, it might be a case of different tuning programs to account for lean emissions crap HD sends out from factory.

HMMMMM, I dunno about that

Seems to me all the trikes in the US are shipped with the same tune

However, the tune may have an update worth asking the dealer about

I am wondering what his shift points are?

Sometimes I wind mine out and shift it a bit later

[trikeman]

Maybe he has a slicker ride than yours.

[ultrafxr]

Maybe he has a slicker ride than yours.

Don't know about that but mine is red and we all know that red bikes are fastest.

[ultrafxr]

HMMMMM, I dunno about that

Seems to me all the trikes in the US are shipped with the same tune

However, the tune may have an update worth asking the dealer about

I am wondering what his shift points are?

Sometimes I wind mine out and shift it a bit later

Typically shift about 3,000 rpm. Only time I wound it out was when passing on a two lane road and only did that three or four times.

I know the moco does do updates to their stock calibrations from time to time. Had one done on my '17 CVO Limited a few months after I bought it. Worth a check for sure.

[DK Custom Products]

Another thing I just thought of...

The M8's have true knock sensors. They don't use the ION sensing that the Twin Cams do.

If a knock sensor is telling it to retard the timing unnecessarily, that could really hit the MPG hard.

Kevin

[Jack Klarich]

Jerry, have a look at this link

Check for codes, you may have a stored code already

This will give you a heads up for your dealer, tho they can look deeper with their scanner

https://www.fuelmotousa.com/p-29661-...ble-codes.html