We have a versatile tranny on our trucks, and I like it. I am curious as to how you utilize the 'M', '1', & '2' positions as opposed to operating in 'D' and selecting a highest gear allowed with the +/- switch. I have found that when running in 4x4L and 'D' the adaptive transmission wants to allow the engine to wind up quite a bit before shifting to the next higher gear. To avoid this and waiting for the tranny to decide to shift I use 'M'. Operating in 'M' the tranny will automatically shift down to prevent lugging the engine, but if you have adequate road speed you can force a shift to the next highest gear sooner than if in 'D'. There is no protection from over speeding the engine. '1' is '1' and it stays in that gear. '2' is '2' and it stays there even from a dead stop. Personally, I don't see any advantage to the '1' and '2' features. Additionally, shifting to 'M' will de-select tow/haul mode. So, how do you use these features?

 

I have found the manual shift useful when driving/crawling down mountain roads. It allows decompression to brake rather than cooking your rotors. I wouldn't use it while towing as the engine "jake" brake assists under 20mph. Once I used it to lock out 6th gear.
That's about all I've done with it.
As far as how to use just shift by the sound of the engine.

 

I use 'D' and the +/- to select a low gear to hold me back in 4x2, 4x4H, or 4x4L as the road condition and load warrants. I'm not clear if there is an advantage, if any, in using 'M'.

 

I use D for general driving.

I use M when towing heavy.

I use tow/haul if the load is rather light and I don't require much engine braking.

I don't lock out any gears. If that were needed I am in Manual mode anyway.

 

I drive in M quite a bit and it's reasonably responsive to driver control input. I use it to hold higher gears which you can't do on any vehicle where the auto trans only offers a 'top gear limit' function. I do it on uphills for example where I can lug around 980RPM and torque it all the way up, also results in faster warm up in the winter.

It's still user-proof though and will still shift if certain conditions are met. There is protection from engine over speed, I regularly downshift to slow down and if you're using too low of a gear for the travel speed (eg. too steep downhill or the truck is heavily loaded and still gaining speed) you will see the torque converter unlock if you get close to redline.

I don't see the benefit of tow/haul on these particular trucks and never use it. Other brands of trucks, especially gassers, I turn them on by default because 'regular' mode sucks. With whatever "engine braking" tow/haul offers, it only does anything AFTER you are already going downhill. With driver control, you can see the incline and anticipate and downshift prior to the vehicle starting to gain speed.

As for 'M' vs '2' and '1'... it's just a faster way to get to those gears than having to press the '-' rocker switch repeatedly depending on what gear you're in I guess. In most situations there is no real advantage over one or the other, other than going from 5 to 2 quickly for tunnels/underpasses and such. That's not a practical use at all though (just a fun one).

Still a little bitter over the lack of manual transmissions being offered on modern trucks, but it's all we got, short of doing an aftermarket conversion, or buying a Ram and getting a G56 I guess.

 

You are correct Trent, the ECM will not allow for engine RPM higher than ~4000. When I first started driving in manual mode and forgot I had it on, I pulled into traffic mashed the throttle got to 40MPH and no faster, why won't this @^#$*& thing go any faster than 40MPH ! DUH! That's all the faster it will go in second gear hitting the rev. limit.
I just wish 2nd and 3rd gear ratios were closer together, there is a big gap there when your trying to slow down.

 

I use tow haul when packing my truck camper, it down shifts sooner and holds back a little better going down hill. I use manual just to play around in town a little.

 

A wide variety of responses!
I use 'D' nearly all the time. With the grades around here and not towing, I will force a down shift with +/- to hold speed back. If I am towing I use the tow/haul mode selected to '6' and allow the machine to downshift as I touch the brakes to employ the engine exhaust brake to hold speed back. We have many 7% or 8% grades here so the tranny features get used. I have only used 'M' to limit engine rpm in 4x4L. Other than to try them out, I have never used '1' or '2'.