Towing mileage report.

[mopar346]

I had mentioned the other day that I had towed a car and trailer for the first time with my dually. It is a C&C 2WD with a 350/400 with a 4.56 70 in the rear, it still has the huge steel flat bed with stake side on it, probably 5000 lbs. easy. I pulled 2 other cars today for a total of 116 miles over the 2 days with some in town, country and interstate driving. It got 8.5 MPG, it has been getting around 12 for regular driving empty. I don't think it is too bad considering and I figure I'll pick up 2 MPG when I switch to a regular truck bed (extended of course).

So my question is what do some of you get towing, please include drivetrain info and the size of the load.

Thanks in advance, Kevin

[86c20]

when i was doing bobcat work the trailer was around 12k and i got about 10 with my 3/4 ton 350 sm465 and 3.42 in the rear. but i live on an island and top speed is 45mph. and i also did some regular driving that most likly helped it too.

[C-10 simplex]

Here's some towing i did:

270.3 miles 17.452 gallons = 15.488 mpg partially with empty trailer
203.7 miles 14.646 gallons = 13.90 mpg 153 miles were loaded with car.
198.1 miles 14.975 gallons = 13.22 mpg all miles were loaded with car.

i normally get 16.5 unloaded with occasional highs of up to 17.8.

The trailer was a u-haul which i assume weighs at least 1500lbs, but probably more and the car weighs a tick under 2000. So we are only talking 3500 to no higher than 4000 lbs.

And yet the truck struggled; This is not a good setup for towing. i had difficulty maintaining 65mph with any incline.

stock 78 305
Th-350C
2.56 rear gear.

The truck supported the weight pretty good, it just couldn't move it so well.

[Firebirdjones]

Originally Posted by C-10 simplex

Here's some towing i did:

270.3 miles 17.452 gallons = 15.488 mpg partially with empty trailer
203.7 miles 14.646 gallons = 13.90 mpg 153 miles were loaded with car.
198.1 miles 14.975 gallons = 13.22 mpg all miles were loaded with car.

i normally get 16.5 unloaded with occasional highs of up to 17.8.

The trailer was a u-haul which i assume weighs at least 1500lbs, but probably more and the car weighs a tick under 2000. So we are only talking 3500 to no higher than 4000 lbs.

And yet the truck struggled; This is not a good setup for towing. i had difficulty maintaining 65mph with any incline.

stock 78 305
Th-350C
2.56 rear gear.

The truck supported the weight pretty good, it just couldn't move it so well.

I guess so,,,a 305 and 2.56's??

[Firebirdjones]

79 1 ton with a 502/400 turbo and 3.73 gears. I pull a 28' enclosed that is 4800 lbs. empty.

With my 4000 lbs car inside, large tool box, air compressor, generator, go cart, and other odds and ends it tops 10,000 lbs easily.

I pull this accross country going about 65 mph, up and down grades, through the mountains etc. For a total of 2,000 miles I averaged 10-11 mpg on every fillup.

Just driving the truck around by itself I get 12 mpg around town and 14 mpg highway. So I loose about 3-4 mpg highway when pulling that trailer fully loaded.

Very acceptable considering the truck and the weight I'm pulling. The truck alone weighs 5400 lbs.

I'm installing a gear vendor unit to knock 6-700 rpms off the cruising speed. I should pick up another 2-3 mpg easily.

[Goldfinger]

85 c10 305/700r4 2.73. Open car trailer weighing in at around 10k with a big ford on it.

Went 250 miles round trip mostly interstate some city averaged about 14mpg. My truck

hated me for this. We maintained 75 until the slightest hill. Never went above 2500 rpm.

Hit stop and go traffic in Mobile Alabama and begged to have had a trailer with brakes.

[74 stepside]

Im thinking the 4.56 gears could be improved to maybe 4.10, 4.11, or 3.73. Im sure you would get a little better mileage and lower RPMs on the highway.

[C-10 simplex]

What i would really like to know is what kind of mileage, both towing and empty, can the following engines acheive:

1) The #12530282 and #12530283 vortec crate engines.

2) the HT 383 from GMPP

[mopar346]

Thanks guys good info, most of the towing will be local but I have thought about a gear swap, I'm just concerned about the 350 having enough power to pull with a lesser gear. Thinking of building a more effeceint engine, I'm not overly concerned about mileage just curious.

C10simplex, there are way too many variables to answer you question.

[PAWS 72]

I'm looking at a 86 3500 single cab with I'm guessing 454 and 4 speed manuel trans. What kinda mpg does these trucks get around town and regular driving.

[Firebirdjones]

That's probably a TBI setup, which has it's good and bad points.

Not sure on the 4 speed as to whether it has any overdrive. I'd guess no on that and it just has a granny gear?

Also depends on the rear gear and the tire size.


My 79 1 ton with it's carbed 454/400 turbo and 3.73 gears with a 29" tire gets 12 mpg around town and 14 mpg highway.

[Corts60]

I tow my camp trailer (about 1800lbs loaded) with my 1/2 ton N/A Diesel and get about 14.5 MPG. Going up a hill is always tragic though

5.7 Diesel
T400 W/ GV overdrive
3:40 rear end

[manimal]

Originally Posted by mopar346

It is a C&C 2WD with a 350/400 with a 4.56 70 in the rear, it still has the huge steel flat bed with stake side on it, probably 5000 lbs. easy. when I switch to a regular truck bed (extended of course).



Thanks in advance, Kevin

I have a 1987 GMC C&C same as yours...weight on it WAS 6290lbs!...And I would be interested when you extend your bed...are you going to leave it a dually? Here is a pic of mine...sorry for the hijack!

[Ski-me]

2004 Yukon XL, 3/4 ton, 8.1L, 3.73 gears.

I know it's not in the 70's or 80's era trucks but good info nonetheless.

Towing from Colorado to Idaho and back. 3,500# ski boat and single axle trailer.

9.5 MPG. 75 MPH is easy with this engine.

Empty, around 12 MPG.

[bilfman]

My buddy has the same truck as yours but with 4.10 gearz. He has absolutely no power issues pulling. Most of the trucks came with 4.10's As for changing gears that is probably your least expensive bit for getting some better mileage if you are thinking overdive etc. A dana 70 gearset is about $165 if you shop around. Keep in mind that the carrier has to be changed too. 4.10 and lower numerically gears use a different carrier then those higher then 4.10. They are a dime a dozen at wreckers.


That said he also picked up 2mpg with tuning. Cap rotor plugs wires and timing. Timing on small block tbi's os set to 0 degrees. If you plan on timing it there is a brown wire to remove before setting it to 0.

Another thing he did, (and I can neither confirm or deny) but he swears it helped how the truck runs, is he took off the intake and cleaned the egr port. He swears it runs and pulls better.

[PAWS 72]

Just wondering. the guy still has it.it is the granny 4 speed.not sure of ratio on rear. have a good day . Jason