I have a 2017 RGU and am considering a stage 2 - all Harley parts. The bike is bone stock.

For those who made the change, how did it effect your gas mileage? I like the range with the stock set up. I'd be willing to sacrifice some of this, but not too much.

I'm gun shy because with a prior bike (2006 Wide Glide), my Indy told me that the performance mods wouldn't significantly effect my gas mileage unless I rode it hard. I went Stage 3 on that bike. Highway MPG went from around 50 to 35. I was always looking for a gas station and the first one that needed to stop.

Thanks
Emil

 

Your going to see a drop thats for sure these M8s can experience problems after the stage updates, like sumping and other issues i am waiting most dont get the sound or the performance they want. Its not like older motors you could do a lot more to them less headaches and no lost of warranty.

 

I know some have had sumping issues after Stage 3 or 4, I don't think I've seen any that have had it from a Stage 2.

My gas mileage may have dropped some, I don't keep track of it. One of the problems is, after the Stage 2, my right wrist is a bit harder to control. It's way too much fun.

 

If I were doing a cam, I would pony up for the latest pump as well.

 

Bone stock I got average of 41.98 mpg.
Stage I- I got average of 39.04 mpg.
Stage II-Torque cam I got average of 36.05 mpg.
I log all fuel burned in the bike using an Excel spreadsheet so this method is about as accurate as you can get. I am an easy rider. Typically ride around 3000-3500 rpms. No WOT events. I have to admit that the Stage II figures really surprised me because I was not looking for that big of a drop in mileage. Still, it is what it is. The long and short of it is "if you want to go fast, you have to pay for it".

 

I did a stage 2 tq at 1000 miles. I left the stock mufflers one and did one tuning session. The bike made 40 to 42 mpg in the first 1000 miles.. It dropped a little at first (39-40) install but after a couple thousand miles it climbed back up.. I've seen as high as 44 mpg but it's typically the same 40-42. Not sure if it's the ecu tuning itself in or the motor breaking in.. Note that I'm still using the stock muffler tho..

 

Not sure what you're riding but 3000 -3500rpms for me in 6th gear equals 80mph @ 3000rpms and 95mph @ 3500rpms. From my experience on a Twin Cam running 80mph for a long haul really cut into my mpg and I don't expect the M8 to be much different.

 

I don't spend all my time in 6th gear. On the highway I would typically cruise at 70-75 mph, which is what the speed limit is.

 

I'm not a wrench turner, so my apologies. What is sumping and how would you know that you are experiencing it?

 

Thanks much for your response. This is exactly the type of information that i was looking for. BTW, what is WOTS?