Poor fuel mileage in N. Central Texas

[Ken R]

Several trips from D/FW to Colorado, South Dakota, New Mexico, Utah, etc. on my 2002 Ultra Classic. The mileage results are always the same:

I get my worst mileage of all the trips up US287 from the gas purchased at the Shell station in Decatur (on 380 just before US287). Mileage has been as low as 30.3 mpg.

I get my best mileage during all the trips with gas purchased in Colorado, even though my highway speeds are 80mph on I-25. Best mileage ever on my Ultra was 47 MPG from gas purchased at a Phillips 66 Station in Fairplay. Sure was nice to go 210 miles without fear of running out.

My friend with his 2010 Limited gets approximately the same mileage on the trips. We ride next to each other, drafting isn't an issue.

Both of our motorcycles are slightly modified and professionally tuned.

Both of our 3,500-mile trips produced overall mileage of approximately 37 to 38 mpg. (It's hard to overcome 30 mpg at the start of each trip).

We both work very hard to fill precisely to the same level in our tanks at each stop. A cup (more or less) makes a big difference in mileage calculations.

Why won't our motorcycles get better mileage? Less frontal area than a car, tuned motors, etc; seems like 40 to 50 would be more like it.

Ken

[alvaro84]

"Tuned" - yes, for acceleration, high rpm power, not for efficiency. And large bikes are ridiculously strong for their weight, so they often operate at a very inefficient range.
And even though frontal area is relatively small, drag coefficient is much worse.
I did not know these things when wanted to buy one to be more efficient (and thus, independent) at commuting than driving a car, but had to learn when I was looking for fuel consumption figures, which were often indistinguishable from small (non-hybrid) cars
But after a long search I could find a fairly efficient motorcycle.
And later another, different one for my girlfriend (though both bikes are small compared to your Harley - a 50hp 650cc and a 28hp 250cc).
And started to learn hypermiling.
Just see my logs
I recommend to look for efficient driving techniques for anyone Anyone who doesn't refuse to try them, of course I, for example, enjoy this game

[Jay2TheRescue]

I could not find specs on the 02, but the 2010 is rated by Harley as 35 city/54 highway. Harley also has a disclaimer that the mileage is under "optimal laboratory conditions". The 2010 is also fuel injected and has a 6 speed transmission, which means your bike's rating would be less.

I struggle to even reach Harley's posted figures for my 2006 Super Glide. FXDI. Harley claims 44 City and 50 Highway in "laboratory" conditions. I'm sure a 6'4" 225 lb rider is not in their laboratory for the test. The best I can figure is they are allowing for a 180lb rider from reading some of their literature. The best mileage I can scrape up is about 42 on average.

As far as your fuel goes, you will get better mileage on ethanol free gasoline, which is what I suspect is going into the tank at your "good" fuel stops.

[alvaro84]

Hm, I browsed through my log but I still can't tell you how much some extra weight and drag counts. I ride 2-up pretty much, but I usually choose faster routes then, and usually do little P&G, so my results are very distorted... but I mostly get sub-80mpg 2-up while I have many 80+mpg tanks 1-up (even a few 90+mpg ones).
I think the difference must be under 10% though, if everything's the same (we're both shorter and lighter than you, though). The problem is, that too many variables are different...

[Ken R]

Originally Posted by alvaro84

"Tuned" - yes, for acceleration, high rpm power, not for efficiency. And large bikes are ridiculously strong for their weight, so they often operate at a very inefficient range.
And even though frontal area is relatively small, drag coefficient is much worse.
I did not know these things when wanted to buy one to be more efficient (and thus, independent) at commuting than driving a car, but had to learn when I was looking for fuel consumption figures, which were often indistinguishable from small (non-hybrid) cars
But after a long search I could find a fairly efficient motorcycle.
And later another, different one for my girlfriend (though both bikes are small compared to your Harley - a 50hp 650cc and a 28hp 250cc).
And started to learn hypermiling.
Just see my logs
I recommend to look for efficient driving techniques for anyone Anyone who doesn't refuse to try them, of course I, for example, enjoy this game

Yes, it's a game, something to keep me interested during those long highway miles.

But tuned for power? No.
Specifically tuned for fuel efficiency. I don't care about top end power.
I didn't mention that I have an Andrews 21N cam (low-end torque cam), head work to increase efficient airflow, and a 6-speed transmission to take advantage of the low-end torque.

Nonetheless, why do my traveling friend and I get such poor mileage from gas bought in Texas versus the other states we travel? The pattern is consistent after tens of thousands of miles of traveling together.

[alvaro84]

Hm, I have other questions:
Do you get bad mileage in Texas with fuel purchased somewhere else?
Do you get bad mileage with the fuel bought in Texas when you go away to a different environment?

And sorry for assuming "tuning" for power I've never seen anyone before to tune a motorcycle for FE, you're the first!

(On a side note: we have an ?urban legend? that Austrian gas is of better quality than that you get in Hungary. Now that I filled in Austria and I got this year's best FE with that tank I still can't justify it as with the tank we filled in Hungary, on the way to Austria I got almost the same FE, 92.4 vs 90.8mpgUS, and again, there were so many differences in the terrain and roads on these 2 tanks... plus the Austrian one started with coming down from a mountain And after getting back from there and started shorter commutes again, FE went down with the Austrian gas too)

[Ken R]

Originally Posted by Jay2TheRescue

I could not find specs on the 02, but the 2010 is rated by Harley as 35 city/54 highway. Harley also has a disclaimer that the mileage is under "optimal laboratory conditions". The 2010 is also fuel injected and has a 6 speed transmission, which means your bike's rating would be less.

I struggle to even reach Harley's posted figures for my 2006 Super Glide. FXDI. Harley claims 44 City and 50 Highway in "laboratory" conditions. I'm sure a 6'4" 225 lb rider is not in their laboratory for the test. The best I can figure is they are allowing for a 180lb rider from reading some of their literature. The best mileage I can scrape up is about 42 on average.

As far as your fuel goes, you will get better mileage on ethanol free gasoline, which is what I suspect is going into the tank at your "good" fuel stops.

Yeah, mine is fuel injected, too. And the cruising AFR is 14.5. Should be good, huh.

My motor is rated at 51 mpg highway. It has never come close. They should reformulate their mileage specifications to at least be within 10% of what a casual rider would get if trying to get good mileage, don't you think? Their mileage estimates are 40 to 60 percent off.


I weigh 155. Riding one-up with about 20 pounds of luggage. Almost all the miles recorded are highway miles within 5 mph of posted speed. And we both meticulously filled our tanks at each stop, trying to get as close to precisely the same level as the previous fill. Of course, that all averages out over a 3,600 mile trip; but tank to tank it matters.

There's always the odd-guy that will claim he got 55 mpg at 85 mph 2-up. Even with 30mph tailwinds, I totally discount those claims. Something is definitely wrong with their measurements or calcs. (filled with less fuel than the tank being measured, speedo off 10%, etc.)

Ken

[Ken R]

No problem, alvaro. I'm somewhat of an anomaly, anyway. At 62, I've long since left the world of high power and high speed.

You ask good pertinent questions:

Do you get bad mileage in Texas with fuel purchased somewhere else?
Usually the last Texas-purchased gas is bought in Amarillo. Next stop, Clayton, NM or Quannah, Texas (depending on which way we were going). Odd, but we almost always ended up stopping at the same stations, whether coming OR going.

In each of the 4 trips, the Amarillo gas produced mileages around 35 mpg whether going North or South. First real improvement is usually noticed with gas purchased in Clayton, NM. On the other hand, the gas bought in Quannah, Texas usually produced the same or slightly lower gas mileage.

Do you get bad mileage with the fuel bought in Texas when you go away to a different environment?
Hard to say. Another factor might be altitude. Clayton is over 5,000 ft elevation. All of my recorded measurements have been in that direction.
Conversely, the fuel bought in Clayton fared about the same going south as the Amarillo fuel when going north.

I dunno. It's just a peculiar phenomenon that I don't understand. With so many datapoints as I've accumulated, the pattern of mileage with Dallas-area gas mileage has emerged.

Someone asked about ethanol-laced fuel. I also recorded the instances of Ethanol versus non-Ethanol in my logs. Rarely see a pump without the warning . . . .er, I mean the notification.

Ken

[Jay2TheRescue]

I am excited that there's another Harley guy here trying to boost the mileage in his bike. I recommend starting a garage entry for your bike, and entering your fuel purchases. I think we can both learn from each other. What motor does your bike have? Mine has the Twin Cam 88 with a factory 6 speed and factory fuel injection.