Towing

[Dwight45]

I've spent most of my time over on the toy hauler forum but since we've been talking about moving from the TH to a diesel pusher this is where I'll ask my question. We've been looking at 34 to 36 feet long, Cummins powered, motor coaches. Most of the ones we are looking at have anywhere from 300 to 400 horsepower. The year ranges from 2000 to 2008, much newer will be out of our price range. Trailer will probably be 20 - 24'v nose inclosed steel. Cargo will be Harley Trike (1300lbs) and Polaris RZR (1800 lbs). We live in Kansas but ride mostly in CO, Utah, WY, and S Dakota so lots of high mountain passes. I'm old school and believe you can't have too much horsepower! So, what do you think the minimum horsepower should be? I know about torque and horsepower but you never see torque numbers on the for sale adds. It's also hard to find big hp numbers in the smaller coaches. Your thoughts and recomendations greatly appreciated. Thanks
Dwight

[wa8yxm]

old guy wrote:
I'm old school also and at least 400 hp

Tim Taylor school of MORE POWER MORE POWER MORE POWER here as well.
(Well he and I are both from Detroit).

One thing I have found. A common belief is the bigger engine won't get the MPG of the smaller one.. There is a curve... kind of like when a teacher grades on "the curve" (That's a bell shaped curve) same for engines.

Too small you don't get the MPG
Just big enough you reach the flat top of the curve
As the hp climbs performance improves. your ability to go up a hill improves. but MPG does not much change till you get to the "Ridiculous" power level range. Not having done any studies on it other than "observation" I'd say if 300 is the low end. 400 may actually get a bit better MPG and likely 600 or more before it starts to drop again.

[doc_brown]

40ft MH with a 350 ISC, pulling a Jeep Wrangler, no issues traveling the mountain west. Usually too fast to be in the truck lane but not fast enough to leave the right lane. Never in a hurry, enjoying the ride!

[John_Wayne]

I would also make sure I got the 6 spd trans. and not the 5 speed trans that went with the 300hp 5.9 engine.

[Blackdiamond]

Make sure you look what engine, you already mentioned ISL, and could probably get away with ISC....do not go for the ISB (660 ft/lbs), just not enough torque. For the Cat engines stay with C9, the C7 at 860ft/lbs is really not enough.

I used to have a 39' with the C7, towing a 20ft enclosed with a Rhino and 3 dirt bikes and was always wishing for more power.

[2gypsies1]

Our 2004 40' Newmar Dutch Star was a 'baby' at 370 hp. It easily climbed many passes in the Rockies towing the Jeep.

[howdy35]

I have a 300 Turbo Cat and have been over the Rockies several times and have never found power to be a problem. Just gear down and climb, then gear down and go down. I have never thought I wouldn't get to the top. I have a 37ft DP and up until recently towed a 2001 Honda Odyssey. I bought the coach because I liked the floorplan and price. I never gave thought that it would not have enough power to go where I wanted. Best to you on your search..


Arnold

[Tom_Barb]

350 should do every thing required. You may not be the fastest kid on the block, but you will get there OK.
High passes are simply time to slow down , gear down and go.

[Mile_High]

I have a 400 hp Cummins pulling actual weight of 43,700 lbs including the Wrangler. It's no race car, but does great over the Rockies (my backyard). I've got an actual GCVWR of over 59,000 lbs.

I think rather than worry about torque and HP (the engineers already looked at that), you need to look at what is left on the GVWR of the coach, and what the actual tow capacity is, because it should be engineered with enough power for all of that. If it's already overloaded or close to it, and you drop a 12,000 lb trailer on the back, you won't be happy with performance.

[Dwight45]

Followup question. Somewhere in this forum was a list or range of engine serial numbers for Cummins ISL (I think) that had a serious problem. Can anyone help me with that? Also thoughts on buying low mileage older units. I found a 2008 with under 10k on it. Thanks again.
Dwight

[Mandalay_Parr]

Mine has been all over the Rockies.

[jplante4]

The "rule of thumb" for DPs is 10 HP per foot. There are several 500 HP 45 footers out there and you may win the race to the top of the hill, but they catch up when you stop for fuel.

Stopping at 2008 also gets you in prior to the DPF/DEF era.

[old_guy]

I'm old school also and at least 400 hp