saggonwaggon91

Ive pulled all sorts of campers over the last couple of years with my 05 2500 4x4 all stock, and have gotten as low as 3mpg to 22 mpg and would normaly run between 65 to 75 mph. The biggest thing ive found is the wind, if in a head wind, run a little slower, tail wind ,***** to the wall

ropnjessi

I just got back from vacation, going through the hills on Colorado, I averaged 10mpg its up and down with long grades. Every where else with flat driving with some 6% grades and driving with the cruise set at 75mph I would average 11 mpg. the trailer weight loaded is 12,000lbs,I would hit 32lbs of boost, and more if I turned the TST up (but in turn the EGT's would rise) I had the Smarty set on 4/0/0/0, TST on 4/0 and PUC on the lowest setting. Egts would not go over 1300* (usually after climbing top of a hill @ 75mph). The truck ran strong the whole trip. I think I will be adding some 50hp nozzles and a Arson III to my setup and call it good.

yellowhemi

Mine gets 15.5 at 60 mph pulling my 1946 Cadillac in hill country.

C Schomer

I averaged 12.89 (100% towing miles) going to Ridgway Co and back last weekend. The 5er was full of water and loaded to the gunnels. A few 100 miles was at 65+mph. I got 22.36 (unloaded) sightseeing at the Black Canyon of the Gunnison and Silverton. Craig

Thundercraft

I just put on a 1200 mile trip with the 5th (about 7000# & 11' high) and averaged 11.91 mpg (us) / 19.76L/100km / 14.3 mpg (imp) hand calculated.
That was with a lot of long, steep hills (8-10%).
probably 60-65 for a lot of it (except the steep hills of course).
Those really long (10-12 mile) grades at 6-8% really suck back the juice.

FunFinder5

I'm half way through my trip to the Texas Valley (South Padre Island). The best tank of fuel so far as been 10.5mpg the worst 7.5mpg driving straight into a 20+mph head wind the ENTIRE tank!

I've slowed it down to 65mph max this trip and I honestly can say it's been about 1+ mpg improvement. I would slow down more to 60mph but the truck just doesn't pull well at that speed. The rpm's are too low and it can't build boost for hills and the tranny ends up downshifting to 3rd. Then it's a fight to make the truck shift back into 4th (overdrive)... most of the time I just go ahead and floor it after I crest the hill and speed up to 68+mph where it will shift into overdrive... then I slow back down to 65mph. If I maintain 65mph it will hold overdrive on almost all the hills I come to.

I agree if I could slow down some more to 60mph or (gulp) 55mph then I'd get better mpg... but there's just not enough rpm's to hold those speeds up the rolling hills we have.

I guess the sweet spot for my truck is 65mph @ 1,850 rpms for towing and pulling interstate hills. I'll just have to live with the 9-10mpg numbers.

rip 112

Pulling my 28' Weekender (6k) I get from 13-15.5mpg, mostly hill country driving or headwinds when going south. Truck yanks it great, plenty of power, turbo spools pretty good if i keep about 25-30% on the pressure box, egts crest 1300* on the hills but you notice the cooling capacity after that because it just levels out.

staarma

I can get between 9 and 14 pulling a 10k toy hauler. It all depends on what the road conditions are. I usually set the cruise on 73 MPH which is 2200 RPM. At this RPM I can pull 7% grades with no troubles but it likes fuel at that RPM too and pulling that hard. If I'm in a lot of curves and have to slow down then I can get 14 being nice. Some of the time I'm in varied terrain with a lot of curves and up and down hills here in the Rockies so I pull anywhere from 5th gear at 60 MPH which is 2500 RPM to 6th gear to 65 MPH which is around 1900 RPM. If I keep it in that range I can average a hand calc'd 14 MPG.

gomulego

it's just my experience, but my truck pulling a 17,000lb trailer at speed limits (65 or there abouts) gets between 12 or 13mpg on average on a highway trip. I sure like my Cummins.

dieselfreak21

Finally got a long enough trip to do some testing throw some more information in. Found 5 HP and 3 TQ on the TST resulted in the best power and fuel milage. Highest egt's was 1175 on a 3 or 4% grade with the stock turbo. Weighed in just a tick over 20k. Average milage for the total trip was 12.2 MPG. Found that if you have rolling hills to not use the cruise. Just speed up a little going down and coast up the hill yielded the best mileage as I got almost 13 on the return trip. Most hills didn't make it flinch and only lost about 1 mph on the big hill in 5th gear. Found running between 65-70 also resulted in lower egt and better fuel milage. did about 800 miles this weekend.

AH64ID

Did my longest tow this weekend..

Towing from Boise, Id to the Bonneville Salt Flats. Total miles 679.1, total gallons 57.527 for a overall average of 11.80mpgs. Total tank average speed of 50mph, GPS moving average was 57 each way. We drove 60-65 most the way, sometimes 70. The entire trip had 20K feet of elevation gain. Weight was 14080 (4860 steer, 4800 drive, 4420 trailer axle) on the return trip with a 1/2 tank of fuel, so it was probably 14,500 on the way down. Started at 2700' and got as high as 6200 feet.

All in all I am pretty happy with the mileage. Trailer is a 18' TT.