StMapleBury
Junior Member
I drove over 100,000 miles with a 2003 Ram HO Cummins optimized with cold air intake, Banks exhaust, economy tune, 3 speed auto with overdrive, towing a 30 foot 8000 lb travel trailer. All manner of conditions. The 2003 Cummins was the last diesel with no emissions additions. No cat. No Def. Mileage unloaded was amazing. I use to dream of what a 6 or 8 speed trans would have done.
I would seldom go faster than 63 mph because gearing would take it out of optimal performance. More important though, and this is what concerns me about folks traveling faster than 60-65; trailer tires aren’t designed for higher speeds.
All that said, keep tire pressure at max for load on the side wall on the trailer to reduce rolling resistance and heat build up in the tires.
Keep the truck tire pressure at the highest recommended for towing.
In my experience a stiff headwind on the the flat high plains would reduce mileage to 9 mpg. The same stiff tailwind would raise it into the 15s. Normal would be in the 12s and if I dropped to 55 I’d get 13 to 14, again wind dependent.
I was surprised by how good mileage could be at 45 mph in 3rd on the Alaska Highway.
I sold that 2003 last year and now have a 2019 2500 6.4 Bighorn. This gasser just passed 5k miles.
We just made are first tow outing and are sort of abiding by the breakin’ rules for towing. So far headwinds kept us at 8 to 10 hand calculated. With gas under $2 (I filled up a few weeks back for $1.10!) my preoccupation is more tech than pocket book.
Rule of thumb:
Speed low (60 or lower) tires up, yields higher mileage.
Speed high (65 and higher) tires low, yields lower mileage (and shorter tire life)
I would seldom go faster than 63 mph because gearing would take it out of optimal performance. More important though, and this is what concerns me about folks traveling faster than 60-65; trailer tires aren’t designed for higher speeds.
All that said, keep tire pressure at max for load on the side wall on the trailer to reduce rolling resistance and heat build up in the tires.
Keep the truck tire pressure at the highest recommended for towing.
In my experience a stiff headwind on the the flat high plains would reduce mileage to 9 mpg. The same stiff tailwind would raise it into the 15s. Normal would be in the 12s and if I dropped to 55 I’d get 13 to 14, again wind dependent.
I was surprised by how good mileage could be at 45 mph in 3rd on the Alaska Highway.
I sold that 2003 last year and now have a 2019 2500 6.4 Bighorn. This gasser just passed 5k miles.
We just made are first tow outing and are sort of abiding by the breakin’ rules for towing. So far headwinds kept us at 8 to 10 hand calculated. With gas under $2 (I filled up a few weeks back for $1.10!) my preoccupation is more tech than pocket book.
Rule of thumb:
Speed low (60 or lower) tires up, yields higher mileage.
Speed high (65 and higher) tires low, yields lower mileage (and shorter tire life)
