Auto vs manual

Most automatic transmissions in heavy trucks are automated manual transmissions. Mechanically, they are the same as a manual transmission. Clutch, range, and splitter in the case of 13 and 18 speeds.

As far as the disadvantages, that, for the most part, seems to be subjective. I have not driven one and do not want to, but on similar threads, drivers who have sing their praises or curse them.

I do know that with additional computer, there are more electric components that can fail.

 

The automatic transmission is just a manual transmission, mechanically operated by air, and controlled by a computer.

 

And whether you have an automatic it manual, the power will be the same. The main difference in pulling is great selection. The driver chooses in a manual, the computer chooses in an auto.
The auto takes guess work out of driving. You will also get better fuel economy than in a manual. At any time, you can over ride the system and go into manual
The above is in reference to the Detroit D12 Automatic.

 

I generally like my 18 speed Eaton Ultrashift MXP. If I'm in a hurry though, I could shift the old manual faster. A good driver will do better with a manual for fuel economy as you can see what is coming up next, the computer can't anticipate terrain.
I'd like to,try an Allison next time.
A few farmers I have talked to like them better than the auto shifts, although one said he liked the Volvo iShift the best. Most like the Allison best as they can put any idiot behind the wheel and they can't hurt anything. Plus they are the best for getting a truck launched out of a soft field.

 

No, not what I said. Auto will more likely have a lower ratio to focus on fuel economy.
What the auto does is take the guesswork out of shifting and throttle position. It will focus on the most efficient way to climb a hill.

But, I don't think you should concentrate on how quickly a truck may or may not climb. If you're buying your own truck, then the largest factor to your bottom line is going to be fuel economy, not speed thru the mountains. You'll get up the hill eventually. So it takes you 5 more minutes. Big deal.

 

That's where you're misinformed. Now I can't speak as to the other trannys and engines, but Freightliner uses predictive cruise control where the computer is in constant contact with GPS satellites and does predict the terrain and tells the ECM what to do for the most efficient driving.
Example: I took the grapevine going north with the cruise set at 30 MPH and the engine held it all the way down. Never touched the brakes.

 

A true auto like an Allison would be much nicer in tight spots IMO (when compared to an automated manual). Smooth take off like in a car, instead of jerking around while you're trying to inch along.