I am still one of the few who has yet to change my pipe.  Still waivering between the CS-one and the Remus.  But was wondering what riders are getting as far as mileage difference when you add an aftermarket pipe.  Since I do ride a lot of long distance rides, mileage and range are always a concern to me.

The CS one is the last exhaust choice I would consider, but the Remus is a nice choice. 2 Brothers, Area P, Leo Vince, Holeshot Performance, and Muzzy are all most excellent choices. I have noticed no change in  gas mileage "Area P" matter of fact I usually average in the low to mid 40's no matter how I ride.

interested in the input this thread will deliver.  shouldnt be that different but it might change slightly.
i think these bikes are a little fat from factory right??

I bought a V&H CS-1 and didnt like it, didnt like the build quality or the sound. I sold it and bought a Leo Vince that I am totally pleased with. I didnt notice any fuel mileage difference with either muffler.

I did a flyectomy, high flow filter, and PC-V at the same time as replacing the stock exhaust with an Area P kit, so it's hard to say if any one component made a difference in mpg's.  If you maintain the same riding style with the aftermarket pipe, you should get at least a slight gain.

after hearing JDs pipe shortened and gutted i think that i my just go that way and paint the end caps black.  sounded real good.

I don't think adding an aftermarket pipe will directly have and adverse effect on your mileage.  It can cause your right hand to have and adverse effect though 

I have a muzzy slipon and a couple weeks ago on a ride with my wife I was getting 47 mpg, blew my mind because I usually only get 38 to 40 when I ride with the "boys"  This was riding 70 mph on a 4 lane too.  I have gotten as low as 35 in the twisties.

I bought a V&H CS-1 and didnt like it, didnt like the build quality or the sound. I sold it and bought a Leo Vince that I am totally pleased with. I didnt notice any fuel mileage difference with either muffler.

Curious what the CS One issues were.

Both when I had the two brothers duals and the slip on two brothers my mpg went down.  Well at least for a few weeks man this bike sounds good with a pipe.  No real difference after getting used to hearing it though.

I just installed the two brothers slip on and my mileage went up. I'm new to the forum and the concours. I've put about 1100 miles on my 2009. I just put the exhaust on and my most recent fillup I got 44mpg. Where I was averaging 38-40mpg.

I guess my right wrist is rather large. No flies, filter, PCV, full "P", 33mpg. average.

No difference with a TB slip-on. Small degradation in the beginning when I had to feel and listen to appreciate the change in sound! Still averaging between 39-42 in daily commuting.

I think my right hand has more to do with my mileage than anything.......