20+ at 65 MPH. 15-16 hauling 2000 lb. slide-in camper.

 

Hwy empty get 17 at 80mph.
City I get 12. Also around 80 mph from time to time.
So I can't complain until I slow down.

 

Average for last 30k all hand calc is 17. Best so far 19.5 from Rochester NY to VA beach. Worst is in the winter about 15ish on cold cold weeks.

 

15-16mpg 50% city 50% hwy

17~ and some change if all hwy....

 

My best is 19.6. Filled up and eased out on the highway, set cruise at 64 MPH for about 140 miles. No stops. Fueled up hand calc'd.

Average everyday driving is 15.4 so far. I do a lot of stop and go.

I have almost 10K miles and I am seeing and improvement with every tank now. I also think that winterized fuel is just about gone around hear, so that should improve mileage as well.

I did an experiment, a very painful experiment that is, a few tanks ago. I drove the entire tank and never let the RPM's get above 2K. And coasted to a stop whenever possible. That increased my mileage about 2 mpg, up to the mid 17's. I have noticed that is the most important thing with these big heavy trucks is to take off slowly. They will guzzle the fuel right down if you race off the line every time. Like I said, it was a very painful experiment. I would rather sacrifice fuel mileage and have fun driving my truck. It amazes me how fast this big thing will get up to speed if I want / need it to.


These are all hand calc numbers, my overhead is consistent but inaccurate. It always reads about 2.2-2.5 MPG high.

 

Best 20.9 mpg. Average seems to be 18-19.5 per fill up. Mixed Lowest was 15.72 Small trailer and plow.


Last 3 tanks... 20.9, 19.13, 19.32, 18.72 (B20) End miles last tank 13,449 miles All hand calculated ..

Smarty Wild #9 with Quad Boost fooler.

I live up on a hill and all my highway miles are on Rt91 in VT which has a lot of hills ... I bet 21+ on a long trip is very attainable once out of the hills.

 

20.5 hand calculated burning B20. BDTD on performance setting.

 

Getting about 17-18 hand calculated with mostly highway driving. I've seen some with better, and a lot with worse. Stock tires and stock under the hood. What do you guys think about running some Royal Purple 15W40 in the engine? I remember seeing somewhere on this board that 2-3 mpg gain was possible running RP in the engine. At $26/gallon for synthetic it'd better last 15K miles.

 

another '03 305/555 HO getting 22+ average on my 600 mile a week commute. Best tank was 23.7 with a very next tank of 23.2 for a back up on a 2400 mile trip. Towing the 11200 GVWR 5er will average 12.5 mpg. All pencil figures. This truck is stock as I bought it to tow and make my long weekly commute.
I post over on RV.net and we always have PSD boys get very upset when some of us Cummins crowd post our numbers.
Big tires/3500 DRW/crew cabs/4x4/4.10 gears/auto tranny/heavy options/city driving/driving style/etc will kill your milage.
JIM

 

on the 05 im seeing 21 to 22 on the highway, in town it goes down to about 20
on the 04 im seeing 20 on the highway pulling a inclosed trailer loaded down and about 19 in town unloaded

 

Best was around 20 going to Utah.
Around 17 city driving.
On the hiway, I try to stay @ 2000 rpm. Iv found that is about 72-75 MPH.
Anything over that and the mileage tanks quik.

 

Brand new first tank 18mpg not to bad just need some miles on her.

 

Average 17-18 mixed between highway and city. Best ever was 22 MPG(pre Edge) with my speed around 65 mph on a cold day.

Lately the truck has been loaded either with a camper or trailer wherever I go and have been getting 12-15 MPG. I think the Edge Juice has given me +1 MPG and I installed in the winter.
I use the Jetta(40+ MPG) for daily activities.

 

all hand calculated:

worst 13.5 winter towing washer/dryers & a butt load of funature in a open trailer in stop & go traffic.

best all freeway with 1000# of stuff from WI to GA 23.3

Average 50/50 city/hwy 18-20 depending one what type of lawn equipement I'm halling in the bed (for me small engine repair biz).

 

Over the 6000+ miles I have had the truck (I bought it used) my calculated mileage is 18.64 This would be mostly commuter miles and mostly empty.