For you guys with the 6.7L and 373s, specifically with the 6-speed auto (guys with the manual chime in too)...What are you getting PER TANK? Not per gallon. I've heard what they are getting per gallon, but what about per tank?

 

Good question because I've recently been doing some complaining about mpg. I only have 1200 miles on this new truck but the mpg is pretty poor especially when towing for the first time (400 miles). I had the truck super full and pulled into the gas station 20 miles after the low fuel warning came on... I got 305 miles out of that tank towing! I was really hoping I could go the 400 miles in one tank; was I sure wrong.

 

Per tank is pretty subjective as everyone fills at a different level of empty. If you want to calculate per tank, just take the mpg and multiply by the size of the tank.

 

I must have been fumes away from running out because 9.2 mpg x 34 gallon tank is 312.8 miles. Being that I got 305 miles then I had less than 1 gallon left... SCARY

 

See attached mileage sheet since new for my 6.7L with 3.73 gears and 6 speed auto. Best miles on one tank was 558, but put 34.5 gals in my 34 gal tank...

 

My average has been around 540 per tank, that's taking the mpg and multiplying it by 34. My driving is mixed between highway and city and so far has been unloaded.

 

Ive been getting around an average of 540 miles per tank. That is mixed driving 65%hwy and 35% stop and go.

 

The most miles per tank so far has been 516.6. My truck has only 7700 miles on it.

Greg

 

I always fill-up around half or just under because I don't like to see a 3 figure price tag on the pump! However, I just put in $105 @ 330 miles (GPS), $3.50 per gallon. Fleet card so I couldn't go around the block where it's $3.29.

 

Loaded with avg 20k pounds at around 70 mph on hwy is around 8.5 mpg which is around 250 miles to tank.

Unloaded on hwy at around 65-70 mph is 600 miles to tank.

Stock tires with 3.73 gearing. Hwy driving doesnt differ as much from driving from 5th gear at 68 mph at 2250 rpms or 6 gear at 72 mph at 1850 rpms. MPG stays same give or take 10-20 miles per tank.

As I have figured out, DONT USE 6TH gear when towing unless you have 4.10 gears and dont get out of 5th gear in bigger road city driving and dont leave 4th gear in slower city driving. These trucks like to lug alot and will kill mpg. There needs to be another tsb on fixxing the lugging problems and from what I have heard, there might be a tsb out next month. MPG has not really gone up since almost reaching 30k miles in 3/4 months of driving

 

'bout the same here. Empty - 15.5 to 16.0 m,p.g. @ 75 m.p.h. Loaded - don't seem to matter how much weight - m.p.g. stays around 9 - 10 @ 75 m.p.h. Doesn't seem to matter much m.p.g.wise running 70 m.p.h. or 75 m.p.h.

 

I have the 6 speed manual and 4x4. I filled up yesterday at 489 miles and took 33.1 galons. Mostly all highway miles on this tank 14.7. (not loaded) I have 6,000 miles on this thing and avrage fuel miles from day one is 11.15 I have only towed about 12,00 or so miles with a 9,000 5th wheel. I wish I had kept my 2001. Fuel mileage on this 6.7 really sucks.
This last tank I added 8oz. Stanadyne. I think this may be helping a little. I seem to feel a little increase in power. (Don't bother to bad mouth me for putting an additive in my tank. It's my truck.)

 

We discussed this subject at length over a few roping steers last week.

I remember well the days when diesel fuel was cheaper than gas.

A number of people said that they were considering going back to gas heavy duties if diesel fuel economy continues to get worse. Diesel is a premium here and since gas torque levels are approaching where diesels were a while back they were seriously considering the change.

I have to admit, I considered it too before I ordered the 6.7.

 

I'm interested in the additive thing. Please keep us updated with how it goes.

Good thing sanity prevailed! On the surface maybe the fuel mileage is not what we'd like. But I can tell you my other vehicle is a 2WD Crew Cab Nissan Frontier with the 350Z engine in it and I was only getting about 1.5 - 2.0 mpg better than my 6.7 Cummins. For what my 4X4 Dodge/Cummins is capable of doing I'd say a 1 - 2 mpg drop is a bargain.

Fuel prices are a different story, but I believe our Diesels will have more fuel options than gassers in the very near future.

 

For the guy's getting the 500+ miles out of one tank, do you get out and push your truck's off stop light's and hills? I barely break 300 miles in one tank and I have had no issues with my dpf or computer glitches. I have about 12,000 miles (trouble free) and have a 3500 dually with 373's and a 6 speed auto.