2022 Dynamax Europa 31ss Hill descent

[Rosedawgz]

We recently had difficulty slowing our RV down on long steep hill. Exhaust break switch on but had to ride the breaks longer than I wanted. Our speed down was 44mph. I haven't yet tried to lower the gear setting or change the mode to normal. Any advice on these setting changes. Mahalo

[AZFoxes]

We have an Europa. My technique is to turn off the cruise control and descend in the same gear I climbed in. Periodic application of brakes is sometimes required. I don’t ride them but firmly apply them to get to the speed I want and then release. When able I increase the gears one at a time or just hit ‘D’ to put the transmission back in auto mode.

Originally Posted by Rosedawgz

We recently had difficulty slowing our RV down on long steep hill. Exhaust break switch on but had to ride the breaks longer than I wanted. Our speed down was 44mph. I haven't yet tried to lower the gear setting or change the mode to normal. Any advice on these setting changes. Mahalo

[CyberShanks]

Depending on the grade, it could likely have a sign stating "trucks use low gears". When we crest the hill and start heading down, I'll start out in 2nd or 3rd gear and increase as necessary for more speed, usually not any higher than 4th. Exhaust brake can run continuously and won't do any harm, just don't let your RPMs get much over 2k. If you need to use the service brakes to slow down, use short firm bursts vs riding them.


$.02


Jim

[cvd]

Above comments are mostly correct, two points:
1) "play" with your trans in manual mode on level ground to get comfortable with up & down shfting. You don't want confusion when you start down a steep hill and need to promptly down shift (as stated above, down shift in anticipation of steep down hill sections).
2) The 6.7 liter ISB engine in Europa's can safely rev a little higher than the ISL's in most other M2 models. No problem with engine braking at 2,200 - 2,400 rpm. Once it hits 2,500 rpm it's time to brake and get revs down to 2,000 range.

BTW - just completed my first extended trip in the new Europa, a 2 week loop though CO. Engine brake worked well.

[1HasBeen]

Don't be afraid of letting a 6.7 rev out. In industrial applications they will run against the governor all day long, and they still last many thousands of hours. The exhaust brake needs revs to be effective.

[DR Quest]

Down shifting and slowing down on the top of the hill will help you. I just came down a 6% grade for six miles with just the engine brake. Started on top in 4th gear at 40MPH and never went over 45MPH. If it speeds up just brake to slow down and down shift one more gear.

[AZFoxes]

The Europa with the 6.7 ISB only has an exhaust brake and the engine power band is designed to operate at higher rpms than the ISL or DD found in Force, DX3 and XL coaches. To operate the ISB at these rpms may sub optimize performance and may negatively impact engine health. I recommend reading the engine and transmission operator manuals for the Europa and, if required, talking to Cummins and Allison technical experts to develop techniques for climbing/descending and overall safe/efficient operation.

[Europa32KD]

I have yet to have a problem on any grade with the B6.7

You may need to slow down. Rule of thumb is to go downhill in the same gear you came up in. Some really steep hills may require one lower gear.

Of note, Cummins rates the exhaust brake as 182hp at 3200 rpm. It really takes some revs to become effective and you won't get much below 2,000 rpm.

[Paddock]

Interesting thread.

Cresting at a appropriate speed to start with is also key to a preferred downhill grade approach. Let the uphill scrub speed to start off with.

Have been towing ~6klbs crossing Appalachian/Rockies/Sierras on Interstates, US and State Routes. As others have shared, downshift Allison (manual mode) on crest to downhill is key. Use brake "stab" technique to reduce speed and let brakes cool. Never "ride".

I have been using speed or ~2.3k RPM to trigger brake stab at (depending line of sight, grade, traffic, etc.). Will have to consider the 2.5k limit. Can't see 3.2k as a good thing, but more exhaust brake retardation at higher RPMs is a good thing vs brake fade from heat build up.

I do wonder if Allison in manual mode has an upshift safety feature to prevent over revs and if so what it would be set at?

Hill decent is a key driving skill to master and become comfortable with. Be safe, have fun.

[Papa Foxtrot]

Originally Posted by Paddock

I do wonder if Allison in manual mode has an upshift safety feature to prevent over revs and if so what it would be set at?

Not in my experience, but my driving style sounds very similar to yours, so I would never have allowed the RPMs to get near overspeed. A wild guess on my part would be that it would not force upshift due to liability reasons; engines being less expensive than lives.

[JC70]

Originally Posted by DR Quest

Down shifting and slowing down on the top of the hill will help you. I just came down a 6% grade for six miles with just the engine brake. Started on top in 4th gear at 40MPH and never went over 45MPH. If it speeds up just brake to slow down and down shift one more gear.

^^^^^^^^

[ErnieSimons]

This is from the Allison 3200 manual: Manually control upshifts and downshifts, if you prefer, when driving in mountains or other kinds of rough terrain. The transmission will not allow you to select a range that will over-speed the engine.