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-   -   Unbelievably bad fuel mileage!! (https://www.hdforums.com/forum/dyna-glide-models/1042391-unbelievably-bad-fuel-mileage.html)

ShortFatMexican 04-23-2015 10:13 AM

Unbelievably bad fuel mileage!!
 
I have searched the forum many times for posts on this issue, regularly since I bought my Dyna in '09. At my wits end with this issue... My problem is that no matter what I've done or tried, I never get more than 29-33 MPG. NEVER. It's been this way since I bought it new. Granted, it is my daily commuter and it's all very short in-town trips (11 miles round trip from home to work not counting evening "excursions" or trips down to the seawall in Galveston). Stage 1 SE air cleaner, SE Race Tuner and V&H Shortshots are only mechanical mods. Been on the dyno three times in six years I've owned it with three different techs. No difference. I still have to stop for fuel like clock work at 120 miles on the trip meter and it always takes a full 4 gallons plus. By the way, it runs like a scalded dog and NEVER pings even in the brutal Texas summer heat. By contrast, my '04 FLSTC gets 45 mpg average no matter what but I use it exclusively for my longer rides. The Dyna is strictly a "bar hopper"... short, frequent rides.

Anyone have any ideas?

boro 04-23-2015 11:06 AM

I get 33 mpg most of the time. I find it really interesting to watch the "instant mpg" and the "average mpg" displays on my PV. Often the instant mpg display will show dramatic stats, like 50 - 70 mpg and above. But, the average is always in the low 30s unless I am on a longer ride without stops. MOCO shows 42 mpg combined on these bikes.

I change gears at 3500 rpm. I don't want to change any lower on a stock 96". Most of my trips are 5-10 mi. And, I cruise at 2800 - 3000 rpm unless I'm on a really level road surface, in light traffic.

Your touring bike may have a different cam that allows lower rpm cruising?

Bottom line is that you can improve your fuel economy, but it may mean riding the bike differently. I'm ok with my fuel usage. The truck only gets 15 mpg.

maddghost 04-23-2015 11:22 AM

Mine gets really bad mileage in the city as does yours. it's all the starts and stops + if you think about it 0 miles per hour = 0 miles per gallon ~ 60 mph cruising is going to yield a heck of alot more mpg's. Get that dyna out for a 200 mile ride on the highway and you should see quite a difference, for your own satisfaction. I don't do alot of city riding, the highway is just 5 minutes from where I live and when I'm out there I'm twisting and passing vehicles constantly and get on average 40 to 50 mpg given the right circumstances

PanHeadRich 04-23-2015 11:53 AM


Originally Posted by maddghost (Post 13946999)
Get that dyna out for a 200 mile ride on the highway and you should see quite a difference

:icon_that: That was my first thought as well. You need to get that bike out on the freeway to see what it's really doing. The mileage you're getting from all city riding is what I would expect.

Jesse_81 04-23-2015 12:21 PM


Originally Posted by ShortFatMexican (Post 13946773)
By contrast, my '04 FLSTC gets 45 mpg average no matter what but I use it exclusively for my longer rides. The Dyna is strictly a "bar hopper"... short, frequent rides.

Looks like that's your answer right there. Run an entire tank through it at 80mph out on the highway and see what you get. I'm sure it'll be far better.

enodrano 04-23-2015 01:30 PM

The Street Bob, with a stock 96" setup, fuel milage rates are High (Highway) 41, Low (City) 34, with an average of 38. It also has a 179 mile fuel range with a full 4.5 gallon tank.

Once you increase the airflow (High flow Air Cleaner, Exhaust, and Tuner) you increase the horsepower/performance of the bike. It is natural for the bike at this point to get worst fuel economy than when it was stock. From what you're describing it seems you are right where you should be. Also, if you are only putting in 4 gallons of fuel to fill it up at 120 miles then I bet you can make it close to the 179 mile rating with the remaining half gallon.

Also, When your bike is dynoed it's most likely done in an air conditioned shop. When the air temperature goes up in those scorching Texas summers the outside air gets thinner making the engine run rich. This can result in poor fuel economy. If possible you should have your bike dynoed/tuned in an atmosphere that closely matches when you ride the bike. You could also create different tuner maps for the varying conditions.

tfalcon 04-23-2015 01:36 PM


Originally Posted by ShortFatMexican (Post 13946773)
Granted, it is my daily commuter and it's all very short in-town trips (11 miles round trip from home to work


Sounds like your problem right there.

decencyxdefied 04-23-2015 01:44 PM

I get 36.2 so says the pv with a heavy right hand

maddghost 04-23-2015 02:02 PM


Originally Posted by enodrano (Post 13947341)
Once you increase the airflow (High flow Air Cleaner, Exhaust, and Tuner) you increase the horsepower/performance of the bike. It is natural for the bike at this point to get worst fuel economy than when it was stock..

I disagree, I run a 107 with stage II heads and it hasn't hurt my mileage as stated above.

And my buddy runs a 107 with stage IV heads ans 55mm TB and he gets more mileage than I.

TinCupChalice 04-23-2015 02:36 PM


Originally Posted by maddghost (Post 13947420)
I disagree, I run a 107 with stage II heads and it hasn't hurt my mileage as stated above.

And my buddy runs a 107 with stage IV heads ans 55mm TB and he gets more mileage than I.


I agree completely, I left my '13 Wide Glide stock for 1k miles to get a true feel for it and how the changes I plan on making would affect it, mileage was low/mid 40's at best. Now with a Stage I and doing multiple autotune runs with the Power Vision the mileage is still going up.

Last Friday I took a leisurely ride with a few friends, we maintained a pretty steady 63 MPH or so/6th gear running back roads and curves, I topped off at just over 100 miles in to the ride, 1.81 gallons of premium, 55 MPG. I figure it's an anomaly. Back home I top off again just before putting the WG into the garage, I never put a bike away without a full tank ;) 114 miles, 2.15 gallons of premium, 53 MPG... The 'Glide is running the best it ever has, strong and smooth and getting surprising mileage, a few more autotunes and who knows how good she might get :D


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