Ok, so many may remember me has having the hands down worst mpg of any rider on this forum at roughly 25 mpg/50 miles the light comes on (all city stop and go/sf hills etc, but still sucks). So anyway, I pushed it as far as it would go somewhat unintentionally (thought I could at least make it to the gas station), and the bike started to sputter at only 70 miles on a fairly busy road. It just felt like it wasn't getting enough and would sort of hiccup, but not die. Scary feeling. When I coasted into the gas station and filled the tank I could only fit 2.8 gallons in there. So that means I still had a half gallon, and maybe I'm doing even worse than previously thought. Does the half gallon left even though it's about to die seem right?

I'd love to get better mileage, but it's not worth spending the money to do. everything runs fine.

 

A buddy of mine has an 08 also and on a trip through Utah, was able to average 40 miles per gallon. Average speed was around 55mph. I know this because his was the only Sportster out of 15 bikes and we had to plan gas stops around his bike.

 

Looking at your signature...is there something you had done when adding the mods that it wasn't tuned right? The WORST mileage I ever got was on a trip back from Wisconsin into a 30mph headwind cruising at 75 mph and I still got 29.9 mpg loaded down with bags and gear. Mine may not be the best mileage either but I'm consistently in the middle 40's and that is riding solo or 2+ makes no difference.

I would look at your setup again...

JM2C

 

I never read your prior post about gas mileage so more info would help. Did you always get poor gas mileage? did it start after the stage one upgrade? you mentioned alot of city driving. Do you like to rev up the bike alot? do you have to be the first off the line at the green light? This affects my milage, I got to be in front of that suv. Could be a bad tune or lead foot.

 

25 mpg sounds like there's something wrong...I can't imagine your 08 Nightster and mine being so different with the same A/C and different pipes.

I used to get 50 mpg but recently it dipped down a bit to about 47 - 48 mpg, and mine runs fine as well. I'm sure rider's weight may factor in but I'm at 160 and doubt that's the only cause of your horrendous mpg.

 

I pushed mine to the limit before and had the same reaction as you. It would sputter on acceleration, especially from a stand still. Milked it to the gas station and was only able to put in exactly 2.8 gal. I was told the missing 0.5 gal is taken up by the fuel pump residing inside the tank.

Too bad about your current MPG, I average around 36 and that is mainly in stop 'n go, but I don't have nearly all the hills you have up there in SF.

 

MPG as low as 43-45 and high as 56-57, gas light always comes on with 1.3 gallons left. Under about 0.7 gallons left the fuel sloshes and some times get misses when riding aggressively.

 

I don't ride like a maniac, but I do lay on it just a touch. the bike had the upgrades when i got it, and the 1st owner who did them worked at the dealer. I bought it from the second owner. If I'm on the freeway or open roads, which is not often, the bike does considerably better, probably close to 40 mpg. The bike runs great, so i don't think there are any problems aside from shitty mpg in the city which is where I do almost 100% of my riding.

 

Gotta be something wrong with your bike. I get 50 or better running around 55 mph in the hills. I get about 45 mpg on the freeway running 80 (NOTE: this tends to cause oil to blow out the air cleaner....). I've gotten as high as 70 mpg, but that was running down hill from Big Bear....

 

If there's something wrong, wouldn't it be noticeable in performance or elsewhere? The bike runs beautifully, feels great, sounds great. Running 55 on open roads I'm getting close to everyone else, it's just in the city it's worse than everyone. Lone Stranger, what is your set up and riding conditions where you are getting 70? Was the bike even on, or just coasting downhill?