cliffy49 wrote:
Looking into....a 2012 F250 with a 6.7 and 3:31 gears.
I realize that 3:31s are not normally the ideal choice for towing but since this is a diesel, it may be different. I realize that 4:10s or 3:73s would be a better choice.
In previous truck generations when 3 or 4 speed transmissions were your only options, lowering the axle gear ratios was the only good way to increase applied torque to the wheels.
Newer transmissions with 6, 8, and 10 gears let the manufacturers reduce axle ratio for fuel efficiency and allows for using lower ratios on gears 1 & 2 to give you 'off the line' grunt even with a higher axle ratio. So, diesel or gas, the increased # of gears in the transmission makes up for the higher axle ratios.
KJ