are current production trucks really this badly built?

Where I see coasting in neutral potentially saving fuel is on a slight downgrade where you need a little bit of engine power to maintain speed. If you cut out the rotating resistance of the engine and can coast at the desired speed in neutral, you might see some minute gain.

All in all it seems like an elaborate waste of engineering and design to save a drop or 2 of fuel.

 

I have no idea how the mDrive or any of the others work, maybe it’s more than just getting the engine to the idle rpm. Maybe the internals do something when it’s coasting that cuts down in parasitic mpg loss.

 

I don't know how it works either. I would NEVER operate any kind of a tranny that knocks itself out of gear without my express input I would quit my job first. I consider this to be extremely dangerous. It can be virtually impossible to get back into gear especially once a truck gains a lot of speed, and they will once all engine compression is removed. Regardless of it is is an auto shifter or a manual, once out of gear it is not easy to get back. Mark my words, this tranny will prove deadly!

 

Paccar, Detroit, and Volvo/Mack are all betting against you. And they have plenty of miles on them already.

 

Company driver on this forum reported being fired for coasting in neutral at 80mph.

 

I don't know how the internal parts work. When it goes in and out of gear for coasting it's instant. It will do it on even small hills. I think it just adds up over time. It does it automatically with the cruise control on. It won't do it if you foot is on the pedals. The first couple days is seem weird. Once you get used to it, let the computers do their thing. Because as soon as you speed drops cruise control kicks in and the truck keeps rolling. If you push on the brakes it will go back into gear. Remember the transmission computer knows every speed for every gear. The computers have no problem and the computers can control the engine RPMs at the same time. My guess would be you put them both together because the engine and transmission can talk to each other. So it can match any gear combination instantly at any time.

 

I hope that the safety record continues. I get no satisfaction being proven right on these subjects and I hope that never happens. Let's just hope I am wrong and stay wrong.

 

Didn’t he have his foot on the pedal and didn’t realize he was going downhill or am I thinking of a different guy?

 

Doesn't matter if you're driving a D13/Ishift, DD15/DT12 or an X15 with an Eaton Autoshift. They all talk to each other. Even a DD15 and an Eaton talk to each other. Its called multiplexing and we've had that tech for decades.

 

You are not getting my point. I am saying the system is now not working. Something has happened. I can tell you right now if there is a long downgrade and there is no braking action or engine compression a driver only has a few moments before the tranny input shaft is spinning at such a high RPM no matter what you do the tranny will not go back into gear. I know of several runaway events that were caused because a driver missed a gear and was not able to get back into gear. I will just repeat what I just said. I hope I am wrong!