My 2011 FLHTK (13000 miles) has 40.3 MPG since new. I have logged every fill up since I got it using a phone app. In January this year I got stage 1 done, SE slip ons, Ventilator and flash, and I added XEID's. I have noticed a slight decrease in mileage (~1-1.5 MPG) but that could be just me playing with the awesome :>) power from stage 1.

 

When I want to go fast I will take one of these two.



But when I want to go 200 mph, I take this one.


My touring bikes are for riding all over the North American Continent in a relaxed style.

 

2black1s -

There are some things about a 4 cycle engine you need to learn. A 12.1 to 1 is the optimum AFR to more completely burn the incoming charge. A higher AFR will not completely burn and is much harder to ignite. Since the power is from the expansion of the burning gas a cooler charge has more expansion capacity both from the more complete burning and from the more dense incoming charge.

A motor set up with a less restrictive air cleaner and stock muffler will have more low and mid range torque. With that the bike requires LESS throttle to maintain a set speed.

The bikes did not run as strong or achieve the mpg levels until the mods were done.

I am only a shade tree mechanic and have been modifying muscle cars from the early 60's on. 409's, 427's , 454's, 455's up to the current date with V10 Vipers and Corvettes. I know how to get the most out of them without cams and boost to get better performance and still achieve longevity and reliability.

 

I always go @ 200 miles on a tank of gas, then have to put 5.5 gallons in - so, averaging 36 mpg.

103 with stock tune, fullsac true dual kit, Rush slipons with 2.0 inch baffles. The trual duals have moved the torque curve.

Run 10% Ethanol 93 octane (no 91 here)... 190 lb rider. I cruise at 3000 rpm (regardless of gear). I also accelerate rather quickly (not easy on throttle)...

I only wish I could get closer to low 40's mpg - forget about 50! I'll never see that...

 

If you want to discuss this further I'm game as long as we can do it civily without turning it into a pissing match. Maybe we can both learn something.

I'll start by asking these questions:

If 12.1/1 was the ideal AFR for a more complete combustion then why is it that there is not a single emission controlled vehicle manufactured today running that AFR?

Hydrocarbon emissions increase proportionately as the AFR becomes richer. Isn't that true? And hydrocarbon emissions are essentially the measurement of unburnt fuel. So... If the hydrocarbon emission levels increase as the fuel mixture is richened, how is it then that the richer mixture could be producing a more complete burn? A more complete burn should result in lower hydrocarbon emissions.

And as for the fuel economy side of this, which is what this thread started out discussing, I'd ask a very similar question. If a 12.1/1 AFR provided the best fuel economy, then why isn't every manufacturer out there building vehicles that run that AFR?

I don't claim to be the definitive authority on this topic, but I think I do have a fairly sound general knowledge of it, and if I can add to that knowledge, that's a good thing.

 

Ok. After reading all of these post I feel I have something wrong with my bike. I have a 06 FLHX carbed with VH true duals, 5 speed, 4+1 tank and stage one. I ran recently a 600 mile all interstate run. Ran 80 pretty much all the time and got 142 miles then switched to reserve. Averaged 33 mile a gallon. I know I was hauling *** but is something wrong?

 

Not necessarily. Your mileage is at the lower end of what most folks report. The 50's you read about in this thread are at the upper end.

How you ride has a major influence. I can gaurantee you that no one riding 80+ MPH gets anywhere close to 50 MPG.

You maybe a little on the low side, but not low enough to definitely say there is a problem with your bike.

My latest trip was about 950 miles at speeds similar to yours and I got 34 MPG (2011 103 Limited).

 

65= good MPG, 70-75= bad MPG.

 

Before I had my motor built and just had a pair of slip ons and breather as long as I stayed in the sweet spot which on that 96 was roughly 2800rpms I could get 48mpg,without wind.
Now on the highway I noticed I don't have as much twist on the throttle to maintain speed. I know the tune had everything to do with mileage and throttle position but my city mileage is no worse now then it was when I was stock.
I believe the guys who say they are getting 50 mpg. Non ethanol fuel and riding in the sweet spot will get you there for sure,however I have a 107 hp bike and even at half throttle you gotta hold in tight.
Fuel injection is amazing. You can tweak and tune and get the motors running way better than any carb'd bike. Tuning is the key. I would love to have a few hours on the dyno by myself,knowing how I ride. I could tune this thing to get 50 mpg on the highway. It would run lean and hot but at speed the heat is a mute point. Fuel injection can modify fuel flow at different rpms/throttle positions and knowing how you ride makes fuel injection far superior to a carb.
Yes fuel injection is complicated,and a pain to tune,but once you got it perfect these bikes run so beautifully.
Like your riding in heaven.
Great thread other than the pissing match. I learned something.
Thanks guys

 

Ditto