Mountain grades

My Volvo has that auto-Jake thing. You set the cruise, and the brake cruise and put it on “A”. But I’ve found it to be basically useless on anything other than very slight hills. So I just put it in manual for the hills I run.

 

I love the way the new Freightliners and the 12 speed auto work on hills like Cabbage and Grapevine. Actually find it easier and smoother to set cruise about where it should be and let it do it's thing rather than run it in "manual", especially on hills that have variations in pitch.

 

No it is not true. The best way is to slow down before the grade and downshift. SAVE YOUR BRAKES. If the gear and will not hold speed, USE BRAKES TO SLOW DOWN and downshift. If you miss, USE BRAKES AND TRY AGAIN. Get it into the lower gear and rest brakes on hill. (Repeat if necessary).

 

In an auto, the tranny won't interfere with the proper operation of the Jake?

 

I like your thinking. I never allowed a trainee to test out for solo unless they demonstrated competence with upshifting and downshifting going uphill or downhill.

IMHO that CDL book advice to never downshift on a downhill may well have contributed to more than a few deaths. Without practice a driver gets into a situation that requires it, then either tries, fails, and panics (Donner Pass?); or they never try and end up frying the brakes to the point of failure. Not teaching the skill of shifting on steep hills is unacceptable.

 

Not the newer autos I’m familiar with. In fact they will improve engine brake performance by allowing higher rpms than a manual will, and keep you in the most efficient gear.

 

Best way in an auto for me is pick my speed, switch to manual, select the gear and set the engine brake. Generally don’t have to touch the brakes or anything, she’ll hold solid around 1900 rpm

 

Why switch to manual? In the DT12 it’s just not necessary and actually feels counterproductive. I don’t care what kind of grade we’re talking about.

 

The engine brake in my Volvo (D13) won’t hold it on its own and it’ll upshift. Putting it in M keeps it in gear for me.

 

I want mine to be in whatever gear it knows will work at the given speed and grade depending on the stage I’m using. Actually most times I find it easiest just to set the cruise at a speed I know works safely and forget about it. I really like the way freightliner has there’s tweaked now. I never drove the older generations but I can’t find anything wrong with this current generation.

Even on steep descents with loose or patchy snow pack I’ll leave it in auto and stage 1 and let it pick the gear based on the speed I seem happy with.