Need some expertise from someone better versed than myself. As I understand it, today, the auto is more valued for offroad due to improvements in gearing (ratios and # of gears), control over shifts, and internal Tq. multiplication.

As far as the Tq multiplication...How much advantage does an auto have over a manual if both have IDENTICAL ratios? Will a ZF6 with a 5.79 granny low still allow more efficient power application than a 6R140 with a 3.79 1st gear?

The reason I am asking is I want to find the most ideal combo possible for increasing tire size, maintaining good cruise performance while still having better than stock off-road gearing.

Am I missing anything? Overthinking this?

Been using this to comparing trannies, gearing, tire sizes etc...
Gear Ratio Calculator

Thanks all.

 

Automatics have always been more desirable for rock crawling but they have limitations like overheating , there's nothing wrong with it manual either if you know how to use them.
pick your poison, which are you more comfortable with?

 

Yeah no rock crawling in my future. My main focus is though, the "TQ multiplication advantage" of autos and how that translates or compares to manuals. The ZF6-750 has like a low gear that is about 75% deeper numerically than the really low for an auto, 6R140... Does the "Tq multiplication" of the auto overcome that difference in the real world?

Even the ZF6 2nd gear is quite deeper than the 1st gear in my 4R100....

 

I don't have much experience 'wheeling an auto, so take this for what it's worth. But what I've read is that the torque converter is equal to about a 2:1 gear reduction. If that holds true, then an auto with a 3:1 first gear would be about the equivalent of a manual with a 6:1 first gear.

That said, that's only when you are trying to put power down. An auto with a 3:1 first gear is worse at compression braking than a manual with a 3:1. Maybe the same 2:1 holds and it's equivalent to 1.5:1 with a manual???

 

But in first gear the transmission is fluid coupled as tourqe converter isn't lock. This produce essesive heat.

Low gears or normal 3.55 gears with.
BlackBox-i NP205 Titan Series

 

I've had too many drained batteries or dead starters over the years to ever willingly buy an automatic.