I am considering buying 2500 or 3500 4x4 CTD manual tranny. I usually pull a 4000lb trailer that doesn't catch much air and usually have about 3000 lb in the back of the truck. I drive a lot on interstate and usually push the speed limit which is 75mph in most western states. What can I expect for fuel mileage? Does anyone pull with similar loads & speeds.

 

I pull about the same combined weith but more air resistance and get 14 MPG towing. Hope this helps.

 

A stock 12 valve with a reasonably light load like you describe will generally get 14-17 mpg running between 70 and 75 mph. They will run in the high teens or low 20's empty. Boost the timing to 14 degrees and you will gain another couple miles to the gallon, and a bunch more power.

 

on my heavy loads I get around12 on the lighter loads I can get around 16. light would be towing my dads small tractor which in around 5000 pounds.
DM01

 

Make sure you get the 3.54 rear if you want the good mileage. After 440k with the 4.10's I'm ready to switch.

 

My loaded (total weight 20,661lbs) weight goes from 9-11 mpg. I usually drive 70-75 mph and the best numbers are durring night hours.

 

12 MPG at 65 MPH. That's with 5500# of trailer and horse.

 

14 mpg pulling a 5000 lbs (dry), 6000 lbs loaded)trail-lite 5th wheel. When I pull my friends 4000 lb trail-lite loaded (3000 lbs dry) I get 13 mpg and higher egt's. I pull at about 65 to 70 mph. Kevin

 

BTW, friends trailer is a travel trailer, mine is a 5th, I guess higher wind resistence is the cause for lower economy. Kevin

 

12000 pound fifth brings me in at 12.5 mpg at 65 mph with the 4.10 gears. 70 drops it about 1/2 mpg. This is a long term average for several thousand miles of towing.

Bill