howdy y'all,

The question is, what rpm range should I be in for the best gas mileage? I have been averaging 40 mpg and cruising between 2000-2500 RPM. the ride is a 06 ultra classic with the standard 88TC and 5 spd.

thanks y'all

 

My 106 gets 42-45 mpg highway. I tend to rev higher than you do though. 2000 rpm is lugging the motor as far as I'm concerned.
My motors sweet spot seems to be from 2600-3000 rpms. At those rpms it takes very little throttle roll to gain speed and the engine sounds like it's not working hard.
At the rpms you stated any significant roll on the throttle will chug the engine,which is really hard on the bottom end.
Try keeping the rpms higher when your cruising. At least 2600 rpms anyway.
A slight increase in rpms will get the engine closer to the powerband which is where the engine is more efficient for the power it's putting out.
It's your bike but no way would I run at a sustained rpms of 2000 rpms. The bike doesn't sound right,mine doesn't anyway.
If you can take the bike on a less travelled sideroad and do some slow throttle rolls in 3rd,4th and 5th and listen carefully to the bike. When it goes from that slow deep exhaust note to a slightly higher pitch and slightly more throttle makes it really responsive,that's the sweet spot. It's hard for me to explain but the bike will tell you

 

Previous poster is correct. I have a 6 speed in my 07. At about 65mph I will get better mileage staying in 5th rather that being in 6th. It has a lot to do with throttle position and how hard the engine is working.

 

thanks guys. i will run it up a bit higher and see how this next tank og gas does.

 

I've been trying to keep my 6 speed 103 at 3000-3500 RPM. That means I'm not using 6th gear unless I can roll at 75 MPH at a minimum. It's tougher to maintain 3000 RPM in higher gears... usually can't maintain it until 4th gear. 1st thru 3rd just seem to feel right at 2500 RPM. Riding like this I seem to maintain 40 MPG. I realize this may not totally address the OP question, but there seems to be a common thought that you're running the RPM a little too low.

 

On my 10 Ultra at 2,100 to 2,600 I get 50 mpg.

 

+1 2200-2400 and I get around 50 mpg.

Speed kills.....mpg.

And so does rpm.

 

I'd like to chime in and mention that I think a lot of chosen RPM's a rider would cruise at depends on the tune. My 103 with baby cams runs effortlessly in 6th at 54 mph as long as there isn't any hills or I need to accelerate rather quickly. I get about 45-51 mpg in Canadian gallon terms. No lugging feeling at all.

 

Here's the secret to mpg. Pick a speed and rpm. Twist the throttle. Not hard and not like a little old lady. Someplace in between. If you accelerate smoothly, keep dropping rpm until you twist the throttle and you DON'T accelerate smoothly. Raise your rpm a couple hundred, and twist the throttle....... if you accelerate smoothly, you're close to your good mpg range.

Low back pressure is the enemy of low end torque. If you opened up your airflow, you lowered your low end torque. Harley's are not sport bikes, they are tractors. If at a given rpm range, you can twist the throttle, and accelerate smoothly, you are NOT lugging the motor.

The above also depends on your weight, the terrain, and if you are riding solo, or hauling a BBW on your rear fender.

I weigh 190, ride solo (wife has her own bike) and run 2200 rpm a lot. I get really good mpg.

If you're hauling weight, you will have to modify the rpm until you can accelerate with a smooth twist of your wrist. If it chugs, your rpm is too low. If it straightens your arms, your rpms are to high.

Lots of variables, and trial and error.

Good mpg also means..... don't get off the bike for a beer every 30 miles. Keep going, keep your rpm constant, USE THE CRUISE CONTROL.

I got 54 mpg labor day weekend. I average 50.



And don't even start on the scissoring your crank thing. The most common way to scissor a crank is by downshifting to far and reverse torquing your engine.

I've been riding Harley's for 46 years.

 

My MPG is running about 40 to 42 and I am spining the engine between 2500 to 2800 RPM
in town and I run 70-75 MPH on the highway. If I ride from 2000 to 2500 MPH drops to about
36-38 MPG