18 mpg

[AHarris]

Jacksonville, FL to Nashville, TN averaging 72mph turning about 2250 rpms. Overhead said between 18. 7 and 19. 4. Hand calculated was 18. 2.



I love this truck!!!!!!!!!!!!!!!!

 

[sam-eye-am]

Must be nice!

I have the 6spd auto and run lower rpms at speed, but can't seem to get those kinds of mpg numbers (same axle ratio) out of my truck unless I keep it under 65

I'd be thrilled to get 18 running 70 down the freeway.

 

[catoiler]

I could not get them kind of numbers even if I was towed behind you.

 

[AHarris]

Just had G30 recall (AX flash and O2 sensor replacement) done on 30 May at the dealer and truck hs 1300 miles on it now (600 since the recall was done). Knock on wood, never had a CEL or any issue of any kind since getting this truck.



I am pleasantly surprised at this fuel mileage!

 

[Garlic]

I'm seeing 18+ MPG cruising empty at freeway speeds (Hand Calc) pretty regularly. Towing it is a different matter. It makes great power and I have a tendency to use it, with 11K in tow I'll get 8. 5 to 14 mpg depending on how fast I want to get there. Just turned 14K on the clock this week. I can't say enough good about the truck.

 

[Coalsmoke]

I've also seen high 18s cruising empty, all in highly mountainous areas. I have little doubt that I'd hit 20MPG if it were in the flats (all hand calcs).

 

[AHarris]

After another 600 miles today the overhead now holds steady at 19. 3 and that's running a mix of nice 72-75mph cruising on the Interstate and 100 miles of 2-lane state hwy through Indiana. I haven't re-set the computer since leaving Jacksonville, Florida 1000 miles ago yesterday.



This truck has me smiling more with every mile!

 

[PaulBarker]

on the highway at 70 my overhead will show a steady 27 mpg, hand cal its about 18. 5 though

 

[CUMMINZ]

Has bit me on the butt. I have towed 2500 miles since last Friday and have averaged 9. 5#@$%! I deleted the MP8 at North Platt.

 

[AHarris]

Update

Truck is now at 6800 miles. Not a hint of problems. Still getting 18. 4 hand calced unloaded. Loaded (6000# of TT and cargo) ranges between 10. 5 and 13 depending on wind and hills).



Very happy except the 6 speed manual is a little on the balky side!

 

[TulsaOkie]

Mine has been getting 12. 4 pulling my 28' with about 6000lbs on it, without a trailer going 65 I got 20. 7 from Florida to Oklahoma. 139k on the engine the 1st year, only the DPF has been the pain in the butt...

 

[rcelum]

Fuel Mileage

Just drove 750 miles from Vegas, Nevada area to Idaho. Got 17. 5 MPG (hand calculated) on one leg at a steady 65 MPH and 18. 9 MPG on the second leg at a steady 70 MPH. Don't know why the 70 speed got better mileage except that it was on more level terrain. I have 19,500 miles on the truck and the last flash was part of the G-30 recall, including the "AV" flash done last October. The mileage has improved significantly since this flash.

 

[JBigelow]

I just bought an 08 in Nov. it has 6K now. I just got 13. 23MPH up from 11-12 I have been getting. I can afford the fuel. But it pisses me off. I thought it would do better. like 14-16. Anyone else in my boat.

 

[Coalsmoke]

My last calculation is 18mpg hand calculated on 100% city driving with 1000lbs in the bed. Of course I've spent a fair bit of money to get there, but it will pay off over the coming years.

 

[tempforce]

i found that i get worse fuel mileage when i buy fuel in california.

must be some sort of additive to clean the air or something. now if i'm not towing i fuel up in oregon, nev or ariz. if i could fit a larger tank or a second tank i could skip fueling in cali altogether. it's usually $. 50 more/gallon anyway.



fuel mileage 10-12 with 10-11,00 lbs

fuel mileage empty 18-24 depending on right foot.

best is around 68 mph.

 

[Coalsmoke]

i found that i get worse fuel mileage when i buy fuel in california.

must be some sort of additive to clean the air or something. now if i'm not towing i fuel up in oregon, nev or ariz. if i could fit a larger tank or a second tank i could skip fueling in cali altogether. it's usually $. 50 more/gallon anyway.



fuel mileage 10-12 with 10-11,00 lbs

fuel mileage empty 18-24 depending on right foot.

best is around 68 mph.

That's pretty good empty mpg, especially it you've seen 24 mpg hand calculated. What sort of things have you done to your truck?



On mine, I'm running Redline synthetic in front and rear diffs, transmission and transfer case, I've got Edge Juice with Attitude (usually leave it on the mileage setting), my truck has 3. 42 rear end and I've deleted the DPF, Nox stuff and EGR. You don't even want to know what my mileage was before all this, it was abysmal

 

[Adventure Bob]

Im getting 20. 6 on the overhead. Havent verified with a fill and mileage but when we did it about 2 years ago, it was pretty accurate.

 

[tempforce]

synthetic oil, light foot, bed cover and keep the air pressure up in the hiway tread tires. and i keep the truck clean.

i stay with the traffic and don't stomp on it when accelerating. i have a load and turbo guage, and i keep them low. speed makes a difference, as i'm in az now, with a higher speed limit and am only getting around 20 average. and the roads are not as flat as i'm used to.

also i have the amp power steps which fill in the space under the cab, outside the frame, so that may be helping with wind drag. and i have the rear end lowered 2 inches.

some examples:

eugene to portland around 24,

redding to bakersfield around 23,

lake havasu to l. a. 18-20

eugene to medford 18-19

all at or near the speed limit.



remember my truck is a 2 wheel drive... .

cc

 

[Coalsmoke]

I'm glad to hear of someone else getting good numbers. I am happy with what I am getting considering that I live in mountainous BC, not too much flat stuff depending on where one goes. However, I'm always looking to improve. You having 2wd will be good for 1-1. 5mpg I would imagine?

 

[dsldoug]

We work on these trucks all the time for hot shoters, We have an 08 POS 6. 7 in owr fleet of 5 dodge cummins and I have not seen or heard of one POS 6. 7 getting 9 mpg or better towing. The high mpg numbers you are posting may be true but are not common by any means.