feedback on 5.9L Cummins with Allison trans.?

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oldryder

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Nov 8, 2017
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Avon MN
Rookie looking to buy.  Occasionly see Cummins diesel.  I know it's a good motor in a pick--up.  Enough motor for a 35' winnebago.?  Other comments?

Thx for advice.
Mark in MN
 
It worked fine on our 34 ft Coachmen, however it is light on the power scale.  So, if you drive with a heavy foot or like jack rabbit starts, you will always be cursing its performance.  But, we used ours for 14 years, 2 west coast trips so over the Rockies and the Sierras, and the torque allowed us to go up and down without difficulty, albeit at a slightly reduced speed.  It gave us reasonable milage and no major overhauls.

Ed
 
Depends somewhat on IF you ever plan on towing anything.

IF you plan on towing a car or trailer then I would look for a bigger motor.
When I was looking for my MH I knew that I would be trailering and going through mountains to get to the place I wanted to go to.
So for me I wouldn't accept or look at anything that didn't have at least 330hp.  But that's just me because I knew in advance
that I would be trailering through mountains - that makes a difference IMO.

IF you never plan (although plans can change) on towing anything and you live in a flatland area and don't plan on
going too far from home then a smaller engine might serve you very well.
 
oldryder said:
Rookie looking to buy.  Occasionly see Cummins diesel.  I know it's a good motor in a pick--up.  Enough motor for a 35' winnebago.?  Other comments?

Thx for advice.
Mark in MN
First what year? I have  one of those little 5.9 Cummins engines in a 38 ft. coach that has ben over every major pass and grade in the US. NO PROBLEM, You need to learn to drive any large coach it isn't like driving your car. Nothing sadder than watching some one with a 330hp and up coach that can't get over hills easily because they don't know  how to drive.
If you have any questions just ask.
Bill
 
The year makes a difference. Mine has 300 hp in a 38 ft dp. I dont find any trouble getting up to speed on the highway, and it takes hills better than my previous v10 gasser. More horses might be better but they do say they are the mileage king. I find mine gets pretty good mileage for a 38 ft coach. Mine has the 3000 series Allison, which I believe is better than the 2000 series. My friend had a 92 Bounder with the 5.9 and it only had 250 hp I think.
 
I just want to add that the accepted benchmark is one HP per 100 pounds GCW (Gross Combined Weight which is weight of loaded coach and anything you are pulling). When some one starts bragging about having 500 hp ask what the Gross Combined Weight is. Some of the heavier coaches are close to 50,000lbs. They perform in much the same way as the lighter coaches with smaller engines. :))
Bill
 
Bill has the right of it. Horsepower is horsepower and if you have enough for the weight of the rig, you will be fine. 1 hp per 100 lbs yields only moderate performance (your car or a pick-up probably has 4x-6x as much power), but it will get you going from a standing stop and climb any mountain, though probably not as leader of the pack in either case.

The 5.9L has come in a variety of horsepower ratings over the years, as low as 190 in the motorhomes of the mid-90's and as much as 340 hp today (in its newer 6.7L form), so you need to query what specific version of the engine is in  a coach and what the combined weight of the rig will be.
 
WILDEBILL308 said:
I just want to add that the accepted benchmark is one HP per 100 pounds GCW (Gross Combined Weight which is weight of loaded coach and anything you are pulling). When some one starts bragging about having 500 hp ask what the Gross Combined Weight is. Some of the heavier coaches are close to 50,000lbs. They perform in much the same way as the lighter coaches with smaller engines. :))
Bill
Definitely. The Beaver I had had a max gross weight of 50,000 lbs and it had 525 HP. My current Ventana has a max gross weight of 36,400 and it has 360 HP, actually accelerating (and holding speed on grades) a little better than the Beaver did, both with the same Jeep toad.
 
For sure. My coach has a gross vehicle weight of around 26000 lbs. Im sure I weigh less than that, but with your ratio of 1 hp per 100 lbs, my 5.9 comes in pretty good with 300 hp. As stated, its all dependent on how much your rig weighs in relation to the hp it has.
 
Everyone; thx for replies.  Now I know to ask about the HP for the specific motor and also ask about HP vs. weight.  Good info.

Best Regards;
Mark in MN
 
People never really have anything bad to say about the 5.9...except it's a small motor.  (likely the best small diesel)
 
I have two 5.9s and have owned four others also.  Never a bit of problem out of them and I run them hard. More important than the horsepower numbers are the torque numbers.  That is what you need for hauling and pulling.
 
gravesdiesel said:
...More important than the horsepower numbers are the torque numbers.  That is what you need for hauling and pulling.

This is a very common - and incorrect - perception. You need HORSEPOWER for hauling and pulling. As Gary said, torque and horsepower are linked, but the key number is the horsepower number, not the torque. 300 hp is 300 hp, whether it's being produced by a big diesel at 1,800 rpm or a small gas engine at 5,000 rpm.
 
uh oh...that always tics off every internet engineer on this forum.    :)
 
A Traveler said:
This is a very common - and incorrect - perception. You need HORSEPOWER for hauling and pulling. As Gary said, torque and horsepower are linked, but the key number is the horsepower number, not the torque. 300 hp is 300 hp, whether it's being produced by a big diesel at 1,800 rpm or a small gas engine at 5,000 rpm.

Or, an electric motor with full torque at zero RPM so it can start moving the cable on a ski lift?  Once it starts moving, then it becomes HP.
 
WILDEBILL308 said:
First what year? I have  one of those little 5.9 Cummins engines in a 38 ft. coach that has ben over every major pass and grade in the US. NO PROBLEM, You need to learn to drive any large coach it isn't like driving your car. Nothing sadder than watching some one with a 330hp and up coach that can't get over hills easily because they don't know  how to drive.
If you have any questions just ask.
Bill

We've been running a "little" 5.9/300 for years as well... up/down one Rocky Mt pass after another for years pulling a JK.  I have to say that on the high passes, with a 6% grade, it won't hold much more than 45 MPH.
 
"I have to say that on the high passes, with a 6% grade, it won't hold much more than 45 MPH."
What gear and what rpm? If you can't accelerate in a gear on a hill you need to down shift till you can. Then keep your rpm near peak hp.
Bill
 
WILDEBILL308 said:
"I have to say that on the high passes, with a 6% grade, it won't hold much more than 45 MPH."
What gear and what rpm? If you can't accelerate in a gear on a hill you need to down shift till you can. Then keep your rpm near peak hp.
Bill

Bill, on those steeper mountain grades, it's often the case that if you downshift, you'll slow down, rather than speed up, at least with a diesel. So I usually let the transmission decide -- it sets shift limits, anyway, no matter which gear I select -- though I'll occasionally downshift a tad early if it'll let me) just to reduce the rate of slowing. There just isn't enough power/torque to accelerate once you've slowed, regardless of gear chosen, on the 5%+ grades. It's not as if it were a manual transmission, or even one with no computer control (rare these days).
 
Many of the new semi trucks with have 11-13 speed automatic transmissions so they can maintain effective speeds up hills.

That technology should be coming to motorhomes soon.
 
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