wrm

06 megacab dually no mods 7 thousand miles 373 rear. 03 ford 6.0 short bed dually 40 thousand miles no mods.mileage has not changed from new so break in should not be a factor.all mileage hand calculated.ford gets 16 to18 normal driving 12 to 13 pulling trailer.dodge gets 17 to 20 normal driving (8 to10) pulling trailer.these milage figures were averages taken on the same interstate at 70 miles per hour over a period of 4 months. what in the world is going on this is killing me.

TonyB

How heavy is the trailer?

My mileage did not start inproving until 8-10k.

rockcrawler304

Towing my Jeep on the trailer is about 6000 lbs and as aerodynamic as a brick and I'm getting 14-15mpg going 70mph. My truck now has 16k miles but the last time I towed and got these figures it only had about 10k miles. This is the truck in my sig.

TKC2000

I also saw an increase in fuel mileage after I hit about 25k. This might be a no brainer but check your tire pressure. Should be about 80psi when loaded and about 60 psi when unloaded. I think that's correct, I could be off a bit though. I had forgotten about the tire pressure when I first started towing my fifth, it was down to about 55 psi. Once I pumped them up I saw an increase in mileage of about 1 - 1.5 mpg. cruising at about 70. I went from 10 mpg to about 11.5 mpg towing 10k lbs. Just turned 57k miles and I average 18 around town, country type driving few stop lights, mostly 50 mph cruising.

wrm

tire pressure is the same on both trucks.hay trailer loaded 14 thousand horse trailer loaded 10 thousand. what i dont under stand is how you can have a 50 persent difference between loaded an unloaded. i ride with a friend who has a 550 with a heavy steel hauler body an a trailer that probaly out weights mine by 4000#.he adverages 9 miles to the gallon with 488 gears.

tcr

megacab dually is probably alot heavier, what kind of tranny is in both trucks? Dodges 4spd auto stock sucks compared to a stock 5spd Torqueshift.

jkitterman

Are both trucks autos? When you are towing with the Dodge, what rpm are you showing? The description of the trailers sounds like you have a lot of aerodynamic drag. You should be aiming to run the engine at 2150-2250 at 65 mph for power/econ.

FAY

wrm, you did not include which type of transmissions the vehicles are equipped with; what the rear-end gear ratio is for the Ford; if both vehicles are 4X4s; what each entire final drive-train gear ratio works out to be; what the size of tires are on each vehicle; what the tire pressure is for each unit; what type and viscosity of component lubication in each vehicle; if the same trailer and total weight is being pulled by the two trucks; if there are lots of grades on the particular Interstate section you travel on; if head or tail winds are a variable factor; if the air temperature and time of day is the same during each truck's trip and other possible contributing factors that I can't think of at the moment.

Your Cummins definitely needs more break-in mileage. The V8 will definitely not be as adversely effected, mileage wise, by high engine rpms as the Cummins. Since the Cummins has low end torque your I-6 engine may be lugged somewhat more often if it has a manual transmission. The pulling mileage you are getting sounds right depending on the load conditions. Aerodynamics of the trailer and ground velocity of the unit are big factors regarding fuel consumption. I don't think you will see much better than 12 mpg.

My tuck engine is not broken in yet, and I am getting 22 mpg empty, but I keep my ground velocity around 65 mph when empty and not over 60 when pulling a load. With a 10k pound load with substantial wind resistance on a tandem axle single wheels flat deck tag trailer and also loaded in the truck box besides the curb weight of the towing vehicle at 55 mph the Cummin gave 18.5 mpg on a dead calm day within the outside cold air temperature for 250 miles. I drive with a very light foot on the fuel feed. My Cummins gave empty 16 mpg from the first full fuel tank, empty 19.06 next, loaded 18.5 next, empty 22.6 mpg next, moderately heavy load in box 22 mpg, empty 22.6 mpg and the engine is not broken in nor is it being driven much at present. I do not think your Cummins engine has any more pollution equipment on it than my engine has.

wrm

sorry about lack of info.both have 373/both are auto an both run at 2000 at 70 ford has 16 inch wheels dodge 17 inch but tire height is the same.as far as wind weather and hills my figures were on a stretch of road 24 miles one way then 24 miles back .this being driven about 4 times a week for over 4 months. im not trying to compare the ford to the dodge its just i cant beleive the towing mileage. im more than happy with the mileage when empty. the trucks being equal what in the world going on with the dodge a 50 percent drop in mileage while towing is !!!!!!!!!!!!!!!!!!!!!!!

Hintz

give it about 10k more miles and you should be good up a couple of mpgs

pupeperson

It sounds to me like you need a timing box of some sort. Maybe a Smarty. The computer in the Dodge may be retarding the timing as it's reading a heavy load factor based on throttle position, speed, acceleration rate, etc. It's probably an emissions thing.

billindenver

Check the stance of your dodge when towing. It is possible the dodge is squatting under the load and presenting more of the truck to the relative wind. In other words..more drag. It's a theory...though I admit a weak one.

Bill

wrm

BILLINDENVER thats not it bill .the dodge is higher than the ford.i lowered the rear of the ford and put timbren load helpers on. it sits level. plan on doing same thing to the dodge, but i dont thing anything like that could make such a huge difference in the mileage. by the way i am completly satisfied with the mileage when unloaded thats far better than the ford an its broke in an is full synthetic

windyr

Hi,

Are both rigs driven by the same driver?

I think that the Dodge is pretty aerodynamic (based on empty mileage).
I get 20+ at 60ish empty but have never ran it 70 for any length of time. With just a 10' Lance cab over camper (11500 GVW) my average MPG goes down to 15-16mpg. I think it is the brick factor more than the weight driving my MPG down.

It is possible that the Hi tech Ford V8 is more efficient at high output than the 5.9. I have never ran on similar trips with similar loads and compared notes with a 6.0 driver.

wrm

same driver me.always thinking about the mileage an how im driving.man i love my dodge when empty.i bought it 235 miles from home an was worried about high speed break in so i drove home on back roads at different speeds never going over 60 miles per hour.averaged over 20 miles per gallon with a brand new truck .but when i started towing that mileage droped to below 9 while the empty mileage stayed great.never have averaged above 20 again but i now drive higher speeds an get great mileage when not towing.