MPG surprise
Stellar HDF Member
Joined: Jan 2017
Posts: 2,678
Likes: 2,081
From: Massachusetts
The octane numbers in Europe are different than here in the states. Your regular fuel at 91 octane, would be considered 87 octane in the US.
Grand HDF Member
Joined: Nov 2017
Posts: 4,251
Likes: 3,134
From: Texas
As a side note, I posted about this on FB Fat Boy group, and got a bunch of people that seem to think even wanting to know the mpg of my bike is getting means I bought it to save on gas, is totally uncool,
and offends their sense of the spirit of motorcycle riding and suggest I buy a prius.
and offends their sense of the spirit of motorcycle riding and suggest I buy a prius.
Some people just can't (or won't) understand that knowing your real-world MPG doesn't mean "I'm broke" or "I'm Greta". MPG = RANGE too.
My stock 3-gallon Fat Bob tank delivered 47 MPG, but I took that bike everywhere, I had it through about 20 states in my first year, and having a lousy 110-mile range until the "low fuel" light came on sucked. A lot. I used to have to carry an extra 1.25 gallon tank because sometimes the little towns in Texas are more than 110 miles apart. And carrying that extra gas sucked too. In a scenario like that, you kind of really do need to know your real-world MPG and your real-world range.
I upgraded to a 5-gallon tank and LOVE it, I don't have to take that spare gas can anymore, and I can easily get 200 miles out of a tank, because my MPG is 47. If I had a 33-MPG bike, even that five gallon tank would only go 150 miles, and that again would suck.
Like you, I was also quite surprised that upgrading to a Stage II came with basically identical MPG. The bike gained a lot of power, and didn't sacrifice any range.
I find it mildly entertaining that usually the same guys who are bitching and shaming you for even knowing your MPG, are usually the same ones lambasting electric motorcycles because of their limited range. Which is (to me) the same issue!
For those who just can't fathom that understanding MPG doesn't mean you're a cucked commie Jill Stein voter, and who do occasionally head out somewhere where there may be limited gas availability, all you really need to know about MPG is: your bike will go a hell of a lot further at <=55 mph than it will at 75+. Stick your arm out -- if you feel a lot of wind resistance, that means you're burning through your fuel supply a lot faster.
Club Member
Joined: Jun 2024
Posts: 414
Likes: 601
From: Florida
Hey, @chunks, a virtual fist bump for your effort and reporting of MPG results. I "try" to track mine, but I forget to track it in any scientific way. Most of the time. 🤷
I have a question for your data, Did you use the HD speedo for the miles tracking? Have you tracked a ride with GPS and compared the miles traveled HD vs GPS? (Not a Rounders comment, this is a serious question)
The reason I ask is that all three of my HD's have had the speedo calibrated Fast from the factory. I.E. The speedo shows 70 while the GPS shows 64 or 65. Many of the HD Fam I ride with on a regular basis show the same type of calibration with differing %'s of error(?).
I had to jump through a few hoops to get my speedo calibrated after changing my front belt pully on the RKS and it matches the GPS mileage within 0.6 miles in 500 miles traveled. And that was after getting the ECM gearing numbers adjusted for the pulley change.
For excess info, my PV3 has a mileage tracking screen and it shows 48'sh most of the time. I tend to believe it as when I'm keeping close watch of the miles vs fuel I get those same'sh numbers.
P.S. Cruse Control on a Fat Boy rocks.
P.P.S. Yes, I did the 34 tooth front pully conversion on my 2020 Fat Boy too. If you try to do that to your 2025, you'll have a few more hoops to jump through to get it done than I had on my 2020.
I have a question for your data, Did you use the HD speedo for the miles tracking? Have you tracked a ride with GPS and compared the miles traveled HD vs GPS? (Not a Rounders comment, this is a serious question)
The reason I ask is that all three of my HD's have had the speedo calibrated Fast from the factory. I.E. The speedo shows 70 while the GPS shows 64 or 65. Many of the HD Fam I ride with on a regular basis show the same type of calibration with differing %'s of error(?).
I had to jump through a few hoops to get my speedo calibrated after changing my front belt pully on the RKS and it matches the GPS mileage within 0.6 miles in 500 miles traveled. And that was after getting the ECM gearing numbers adjusted for the pulley change.
For excess info, my PV3 has a mileage tracking screen and it shows 48'sh most of the time. I tend to believe it as when I'm keeping close watch of the miles vs fuel I get those same'sh numbers.
P.S. Cruse Control on a Fat Boy rocks.
P.P.S. Yes, I did the 34 tooth front pully conversion on my 2020 Fat Boy too. If you try to do that to your 2025, you'll have a few more hoops to jump through to get it done than I had on my 2020.
Seasoned HDF Member
Joined: Oct 2010
Posts: 5,297
Likes: 2,389
From: Florida
Grand HDF Member
Joined: Sep 2009
Posts: 4,556
Likes: 1,846
From: Albuquerque, NM
Did some real world calculating of my fuel economy........
........As a side note, I posted about this on FB Fat Boy group, and got a bunch of people that seem to think even wanting to know the mpg of my bike is getting means I bought it to save on gas, is totally uncool,
and offends their sense of the spirit of motorcycle riding and suggest I buy a prius.
........As a side note, I posted about this on FB Fat Boy group, and got a bunch of people that seem to think even wanting to know the mpg of my bike is getting means I bought it to save on gas, is totally uncool,
and offends their sense of the spirit of motorcycle riding and suggest I buy a prius.
EDIT: I routinely get right around 50mpg with my 114 Heritage. I didn't realize I was a moron for monitoring that.
Last edited by Crazy; May 19, 2026 at 04:26 PM.
Cruiser
Joined: May 2017
Posts: 231
Likes: 222
From: New Jersey
Thread Starter
|
Road Master
Joined: May 2005
Posts: 1,101
Likes: 425
From: Pennsylvania
Hey, @chunks, a virtual fist bump for your effort and reporting of MPG results. I "try" to track mine, but I forget to track it in any scientific way. Most of the time. 🤷
I have a question for your data, Did you use the HD speedo for the miles tracking? Have you tracked a ride with GPS and compared the miles traveled HD vs GPS? (Not a Rounders comment, this is a serious question)
.
I have a question for your data, Did you use the HD speedo for the miles tracking? Have you tracked a ride with GPS and compared the miles traveled HD vs GPS? (Not a Rounders comment, this is a serious question)
.
Well I went by the speedo, but now I'm going to have to do a GPS tracked run for comparison
Edited to add: some quick research shows that while HD speedometers ARE known apparently for reading fast on speed, but their milage tracking is extremely accurate as long as you are running the factory wheels and tires
On the cruise control, its very new to me on a bike. I'm on Fat Boy #3 but neither previous had one. I turned it on once to see how it worked and the first time it rolled on the throttle kinda hard while on an uphill grade without my input it freaked me out and I turned it off
I havent taken any long trips on my 2025 yet, but im sure when i do ill get used to it fast enough
Last edited by chunks; May 23, 2026 at 02:01 PM.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Thread Starter
|
Road Master
Joined: May 2005
Posts: 1,101
Likes: 425
From: Pennsylvania
I just bought a 2022 Fat Bob. Love it, but I'm a little concerned too about the range, coming from a 5-gallon Heritage tank. Just filled it up for the first time, and noticed the "range" setting said 205 miles. I must have a special Fat Bob or maybe mine gets 67 miles a gallon!
Thread Starter
|
Road Master
Joined: May 2005
Posts: 1,101
Likes: 425
From: Pennsylvania
Classic, so it's not just me. I have a 1973 Yamaha RT3. It has a slight oil leak I'm trying to hunt down. I posted on a facebook vintage yamaha forum a video of it where I found some oil collecting on the frame, one of the first comments, 'bring it to a mechanic, you don't know what you are doing...'
