How critical is axle ratio?
In the modern day of 10 speed automatics, how necessary are 'towing' gears? By 'towing' I mean anything over 4.xx. These new transmissions have such low first gears compared to just a decade ago, is ...
Forum Discussion
Hemling wrote:kellem wrote:
Have the 7.3 with 3.55 gears and while towing a 30ft 7600# trailer at 65mph on the interstate, I always lock-out 9-10.
Truck runs at 2100 RPMS and rarely downshifts.
Empty getting 17.5 mpg highway.
Towing-10.5 highway.
So, when you are not towing, does it use 9th and 10th? What RPMs and MPHs do you see then?
They could be used downhill or with a stiff tail wind. Otherwise 9 & 10 are not useful or efficient gears for any sizeable trailer towing.
Especially with high gears like 3.55s and the bigger diameter tires that are common on newer trucks.
