Timekeeper10, your mileage seems about right. If I'm not mistaken the '06 was 88ci with a 5 speed. correct? My previous bike, an '04 EGU got 42-45 mpg highway and 39-40 on the back roads. It had stage I/II.

 

Correct. Its my first Harley and I am loving it. Going in for service next month to an indy in my area. My only concerns are a vibration at 1500 rpms. Might be normal. At this point I am not always sure what normal is except that I want to be riding when I am not working ( and even when I am). Pretty sure thats normal.

 

36 across all RPMs at all speeds, in town and on the highway. Was running real rich before this last dyno (#3 in 6 mos) and even with it leaned out, 36 on a good day. Just wondering if the first owner put cams in it and the shop is trying to tune it to just stage 1. Whatever. Just sucks to get worse mileage than a car that weighs 3x more than my tractor.

 

You have a stage 1 or just stick? I'm damn lucky to get 42 MPG.

 

2010 SG W/ 103 stage ll (blah blah blah- see below) and she seems to really feel good from 2800-3000. At 70 mph in 5th she's just humm'n along at 3000 rpms and lov'n it. Gotta be doing a constant 75 or better to make it worth going into 6th
I really don't give much thought to mpg and never really clocked it
Going to Laconia next week, 300+ mi each way, sounds like a good time to see what I get from her on the highway

 

36 MPG is way low for your bike. My buddy's '09 EG has a Stage I, and he consistently gets 44-45 MPG highway running at 65-70 mph.

 

... and is probably screwing up the math!

 

Took the words right outa my keyboard.
That said, I can see perfectly level no-pothole straight hiway cruise control set at 50-55 pushing 50 mpg.
I did get everything but (49.97mpg) on one tankful on the 117" heritage, but conditions were perfect; most of the time I had difficulty controlling the right wrist and it was hi-30s.
These days I track every tankful, but more for consistency and engine monitoring rather than trying to set mpg records. Like someone said, ride every road the way you want to and enjoy the ride -- set mileage records in your cage.
I wanna feel like it's been a great ride when I get done and not weary of feathering the throttle and worried about whether to accelerate quickly to pass or wait until there is a good 3 minute opening to overtake a 56 mph cager.... but that's just me.

All that said, at the point the engine is just coming to or at the peak torque point is the best rpm for achieving mileage. As accurately pointed out by several posters, it's the max engine vacuum that produces the most efficiency. Just my 2 cents.

 

Great info. Answered a question for me. I have an 06 RKC, 95 inch, stage II. I also put in the SE Six speed gear set. Sixth gear is OD. Once going down the Natchez trace in 5th all the way running between 50 and 55 and riding two up, I got 50 MPG. In Sixth running 70 to 75, I get 42. If I am understanding what y'all are saying, then running in the "sweet spot" at higher rpms provides better efficiency than slightly lower rpms. Another question...does this also have anything to do with the fact that our "tractor engines" are air cooled and are more efficient at higher temps?

 

Absolutely calling BS here! My 103 gets 31-33MPG and that is it! In town, cross country, 2 up, solo on the freeway, no way in hell im ever seeing 50 MPG.

Steve