DX3 driving power question

[4DayJeep]

I have been reading lots of these threads - I plan on using our unit on order DX3 37TS to go cross country. Do these units have plenty of power to pull the grades?? Not looking at going 70 MPH over the grades on Hwy 80 or ones like the grapevine on I-5, but don't want to drop to 30 MPH either. Wondering since I saw you could upgrade to the M2-112 chassis and get another 100 horsepower and 250 more ft/lbs of torque.

[Webefine]

I have a 2015 36FK DX3, I think the power is good. Most of my travels so far have been through West Virginia which has some very steep hills. I normally carry full water, have a fully stocked RV and tow a 5,000 pound trailer. With this set up traveling on rt 79 & 19 in West Virginia and rt 68 in Maryland I never go slower than 50 and that is only on the really long hills. That being said there are times like merging on a highway it would be nice to have a little more HP but overall I think it does pretty good.

[joet19711]

I agree with Webfine, I travel those same highways and pull 4,000 car

I usually use the "economy mode" and shift it when I think it needs it.

Or just stay in the "performance" mode and can maintain 55 or 60 up the

5, 6, or 7% grades with no problem.

[rskeans]

How do you know when you are in economy mode. Is it the display that says 6 6 or the other that says 6 6/mode or something like that.

[joet19711]

Originally Posted by rskeans

How do you know when you are in economy mode. Is it the display that says 6 6 or the other that says 6 6/mode or something like that.

On the Allison 3200 transmission, when you start the engine, the default is the performance mode, and it will always default there.

To go to the economy mode, push the mode button and now you are in the econo mode. You can shift gears as you think needed or you can just let the transmission do it automatically.

Hope this helps.

[rskeans]

That does help. Many thanks.

[dmax36]

We have a 2015 DX3 36FKS and live and travel in the western US. We have over 24,000 miles traveling many of the steep grades, including a 14 percent grade in southern Utah. Many long 6 and 7 percent grades. When entering a long uphill grade we will select 4th gear at which 2000 rpm will give us 45 to 50 mph (not the 14%). We typically travel at 31,000 GVWR towing 3500 lbs. I have never seen a reason for more HP or Torque for our needs.

[retired18whler]

dmax36, we also have the 2015 DX3 FKS... do you know what the "S" stands for?
We go east and west for our trips from Nebraska and haven't had any gripes about pulling grades at a decent speed.

[4DayJeep]

Thanks for the input - sounds like it will be just fine for me. I thought the model was 36FK for front kitchen, but it could be Front Kitchen Slide since the kitchen is in the slide.

[retired18whler]

Thanks, that makes sense, we'll go with that explication.

[jkoenig24]

You don't say what year or engine your DX3 has. I have a 2015, DX3-37RB. It has a 9 liter, Cummins ISL engine set to put out 350HP. I've been out west in the mountains pulling a 26' enclosed car trailer that contained a Prius and a Honda Silverwing scooter. I had NO trouble. PLENTY of power and, had NO trouble maintaining highway speeds (even uphill).

[4DayJeep]

The new unit will have the cummins 8.9l with 350 horsepower and 1000 ft/lbs of tork - with all I am reading it is going to be just fine for what I need. Just looking forward to getting the unit in hand. Thanks for the input!!!

[FOURWHL]

Towing about 8k (36k gross) I don't feel under powered going through the rockies on I70. Sure it slows down, but I can maintain 45-50mph on the steep parts which is usually more than the semi's I'm trying to pass. Is she working hard? Hell yea, would a few more HP be nice? Sure. Is it needed? No I dont think so. Plus those super steep parts are so few and far between, even though we've crossed twice this year I'm happy with performance.

[4DayJeep]

Thanks FOURWHL, that gives me the confidence I need. I don’t mind slowing down, just don’t want to be slowing down to 20-30.

[RV Randy]

Originally Posted by FOURWHL

Towing about 8k (36k gross) I don't feel under powered going through the rockies on I70. Sure it slows down, but I can maintain 45-50mph on the steep parts which is usually more than the semi's I'm trying to pass. Is she working hard? Hell yea, would a few more HP be nice? Sure. Is it needed? No I dont think so. Plus those super steep parts are so few and far between, even though we've crossed twice this year I'm happy with performance.

I'll be loaded and towing about the same as you. How do you like the downhill parts i.e. does the jake set on full do a good job of holding the rig back? How about the brakes? Did you get the factory installed brake controller?

[FOURWHL]

Jake brake on high and 4th gear is the ticket for downhills. On the longer 7-10 mile long steep sections I probably manually brake it from 55 back down to 45 three or four times. Rest of the time I just ride the Jake. Feels very comfortable. Any faster and you'll end up in 5th which wants to run away quickly. Tried it once... never again.

I've got the prodigy p3. My unit didn't come with the controller

[tnrzryd]

Hey FOURWHL - what rpm do you like to hold as a minimum when climbing? I’ve always watched the tach and manually downshifted to hold the rpms up to prevent overheating. The sweet spot on my last coach was 1500.

[bkballard3]

Hi there regarding the transmission mode selector, not all are programmed default for performance mode as was the case for my 2014 DX3 37TS, if you find it sluggish on hills try activating the mode switch to improve the performance. I had my re-programmed to default to performance and the mode button activated economy mode. Hope this might be useful.

[jkoenig24]

bk, HOW did you reprogram the transmission?

[bkballard3]

Sorry about that I took it to an Allison Transmission shop. They confirmed it had been programmed to economy mode as the default. They reprogrammed it performance mode as the default. For me in CA it makes way more sense lots of hills here.

Brian