Fuel Mileage

[Truckdogg4]

I have a 2021 Goldwing CSC DCT Trike. When I fill up it states 189 miles to empty. I have an axiullary fuel tank. How do I tell if I am getting and extended mileage range. What mpg should I get?

 

[pwhoever]

I usually do it the old fashioned way using the odometer. The next time I fuel up I take the miles driven from last fill-up and divide by the amount of fuel I just filled up with. I am not a fan of the distance to empty indicator. The miles to empty can change quite a bit during the ride depending on terrain, speed, etc... It is not an option on the 01-17 models and I'm fine with that. I do have it on my Chevy pickup but rarely look at it.

I don't always check the mileage but do it a few times so I can figure out at what point based on gas gauge, I will need to fuel up. As far as average mileage, again, I don't have a 21 but on my 07, I could easily and usually get about 200 miles out of just the 6.6 gallon stock tank (I have never had the aux tank) so that worked out to about 33 miles to gallon. Sometimes I got more, sometimes less but I would always start thinking about refueling around 180 miles. If pulling a trailer, mpg would always go down so I might get around 28mpg.

Now on the newer 18+ models, I have heard they get better gas mileage but IIRC, they also have a smaller tank from the previous models. I don't recall what they average as far as mpg. The miles til empty will get calculated by amount of fuel in tank and doesn't consider the extra amount in your aux tank.

Now it is possible over time especially if you let tank run down that it will "learn" and update to show a higher miles til empty but not sure. It's possible that the OEM gas tank size is programmed into computer and reads the efficiency of the running motor. I just don't know. In that case, you still are stuck using the old school method for several tanks and then you will get a baseline to follow.

What has been my experience is that from bike to trike, the avg mpg only dropped slightly. I had the benefit of having my 07 bike for a few years and then converting it. I only noticed maybe a 2-3 mpg drop.

 

[Ironhorse54]

I’m getting about 38 MPG on the trike. I was getting 48 on two wheels and was told I would lose 3–5 miles per gallon. So I’m not real happy with this but what the hell. No point in crying over spilled trike lol. The gas mileage gauge from full to empty is exactly accurate when I check manually at the gas pump. When filling up on the two wheels, the gas mileage was showing around 240 or more. On the trike it is showing around 190. That’s because the computer knows you’re burning more gas and it recalculates what the mileage range is.

 

[pwhoever]

I’m getting about 38 MPG on the trike. I was getting 48 on two wheels and was told I would lose 3–5 miles per gallon. So I’m not real happy with this but what the hell. No point in crying over spilled trike lol. The gas mileage gauge from full to empty is exactly accurate when I check manually at the gas pump. When filling up on the two wheels, the gas mileage was showing around 240 or more. On the trike it is showing around 190. That’s because the computer knows you’re burning more gas and it recalculates what the mileage range is.

Just to throw some more stuff in to the game. Have you compared your speed to a gps to verify it is the same as before? The reason I bring this up is the rear end gearing and tire size on the trike may be slightly different than what the rear end gearing and overall tire size may have been from the bike. It's possible that The odometer may be reflecting that you are covering less ground and therefore your mpg will be lower. A straight out 10mpg drop seems to be a bit much. I'm just curious to see.

 

[pwhoever]

Just to add, maybe you're also having a bit more fun and not practicing throttle discipline which can also easily result in a drop of mpg.

I know that if I'm traveling with a group, I tend to travel at a more consistent speed and have actually gotten almost 40mpg a few times. When by myself, it just doesn't happen. And if I creep towards 3000 rpm while rolling down the road, my mileage suffers. And well past 3000 rpm, it starts dropping quite a bit more.

 

[Ironhorse54]

I have not checked it with GPS as I don’t have it on the bike or now trike. But I did check it both ways on two wheels and 3 wheels through radar and it is exactly the same speed.

 

[Ironhorse54]

I agree 100% with your last post and I’ve also gotten the same results.

 

[cScjhb]

Many years and a few hundred thousand miles on different GL1800s experienced right at 40 MPG while touring. My old 2008 GL with CSC trike was right at 36 MPG while cruising in the same fashion I did on 2 wheels. Your newer trike will probably do a little better. I also had an aux. tank on my trike but usually did a fuel stop well before I was below 1/4 tank. I would totally ignore your computer indicator of range. They are unreliable and yours doesn't know anything about your extra fuel capacity.....

 

[Ironhorse54]

Just to keep this conversation accurate, I don’t have the auxiliary tank.

 

[NJMike]

Next time I’m on the interstate I’m gonna set the cruise control to 60mph and check the time between mileposts.

 

[HDUSA1]

I retired from IDOT and had Sign Shop crews who used to set the milepost markers. I would caution you that the distance between them may not be 100% accurate, especially if there is a curve in the Interstate as the distance is measured in the center of the median. If you take an average of say 10 miles on a straightaway, they will be accurate.

I’ve got an iPhone and downloaded a free speedometer app that is VERY accurate. There are several speedometer apps out there, but the one called “MPH/KPH Speedometer” by “Burnt Slice” is super simple to use and the one most gearheads use when making speedometer calibrations.

I did check my 2020 HD Ultra that I converted with a Roadsmith kit and the speedometer was actually almost spot on. When it was a 2 wheel bike, 60 mph on the speedometer I was actually going 58 mph.

 

[cycle7447]

I have a 2021 Goldwing CSC DCT Trike. When I fill up it states 189 miles to empty. I have an axiullary fuel tank. How do I tell if I am getting and extended mileage range. What mpg should I get?

I am not certain I fully understand your question. How do I tell if I am getting an extended milage range.

If your question is - does the 189 miles shown include the miles with the added aux tank, my response would be on.

Some questions you may ask yourself. How many galloons is my bike tank and how many gallons in my aux tank.

I have a Harley - concerted with a CSC trike. When I fill up, it usually shows about 240 miles for my 6-gallon tank. That is about 40 mpg. Before the conversion, I could average about 43 mpg.

If you go to the Harley site and look at the Ultra, it says 43. If you look at the trike, it says 42. So, I am pretty impressed with my 40 on the CSC conversion. Keep in mind, I am not a hard rider.