How Much Horsepower?

[WardH]

I'm a newbie, testing the waters, looking to purchase our first motorhome. We live in Northern Utah and my question involves power - how much do we really need in a motorhome. We're still deciding on things like length and manufacturer/model, etc, but we will definately be towing a Jeep Cherokee behind us. Out in our part of the country, it's hard to go anywhere without having to pull a few mountain passes to get there. Is 450 hp enough? Do we need/want more? Thank you for your educated and experienced opinions.

[Cousin Ed]

We have had 4 MHs from 320 HP V10 to a 355HP V8, a 360HP DP and now a 450HP DP. None were a sports car and all got us where we were going in about the same amount of time. We have crossed the country many times; driving over 200,000 miles In so many words anyone will work.

[Skip Y]

Are you talking gas or diesel? If gas, then you're limited to a Ford V10 with whatever that horsepower is. If diesel, then there are many options. However, once you decide on a floorplan and mfr, then you will get whatever platform that mfr builds on (most likely Freightliner). Remember, torque is what pulls you up the hills, HP is what accelerates you from a stop. We have a Cummins ISC (8.9L) in our 32,500 lb coach and tow an Equinox. Engine has 1050lb-ft of torque and we pass most trucks going uphill.
Also, you're going to be spending much more time living in the coach than driving it, so make the floorplan and mfr your first priority. Take your time and enjoy the scenery, you're not in a sportscar.

[STRich]

Greetings Ward and welcome. Your question is a bit open ended and so very hard to answer because, it depends..... With an RV, HP is only part of the answer, a bigger issue will be torque, and then you have to close the loop with how big is the transmission in the RV along with factors like gross combined weight rating and such.

My RV is only 450hp pusher, but has 1550lb-ft of torque with the large 4000 series Allison trans. This combo ends up giving me lots of towing and cargo overhead.

Depending on the coach, you could have a 450hp engine with only 850ish lb-ft of torque, but if it had also the small 2500 series trans you would not have a bunch of overhead for towing.

You came to the right place to ask your questions and I am sure others will do a much better job than I with detailed info.

Good luck on the hunt,
Rich

[DADSDOGHOUSE]

Fellow Utahn here, I also have had several prior Rvs inpy past, from a small 19" clas C with a 318 gas motor that barely made it over the pass to get to Mirror lake sputtering at 15mph tops. Next had a low compression (7.8 yo 1) 440 Chrysler in a 29" Voque class A, burned 1 or 2 spark plug wires on every trip, carried spares. 40' Monaco with 300 hp Cummins 10liter with a 4 speed Allison, every long pull I would have to pull over due to marginal cooling system. Now I have a 44' Beaver with the big block CAT C-13, 525 hp, no issues on the big passes with cooling, 1st thing I did was a cooling flush with CAT cleaner and distilled water flush. Best thing to be also aware of is need for true compression brake on a Diesel motor, the Monaco just had a exhaust flapper Jake system, not much help on our long downhill grades into towns here. Good luck with your hunt!

[Alpine36]

The minimum “rule of thumb” hp requirement on a diesel pusher is 10hp per 1k lb of GCVWR. Example, 42k GCVWR = 420hp.

[Skip426]

There is an old ratio of 1 HP per 100 lbs of vehicle (s) weight .

So if your loaded coach and toad weigh in at 40,000# then 400 HP is adequate.

My current coach and toad I run down the road at 107 #/1 and I get everywhere I want to go , as fast as I want to get there , way faster on hills than a loaded semi.

As mentioned ; you need to consider the whole drivetrain ; certain transmissions will limit the tow weight rating and GCWR of a coach .

[dmctlc]

Originally Posted by WardH

I'm a newbie, testing the waters, looking to purchase our first motorhome. We live in Northern Utah and my question involves power - how much do we really need in a motorhome. We're still deciding on things like length and manufacturer/model, etc, but we will definately be towing a Jeep Cherokee behind us. Out in our part of the country, it's hard to go anywhere without having to pull a few mountain passes to get there. Is 450 hp enough? Do we need/want more? Thank you for your educated and experienced opinions.

So you'll get a lot of opinions on this subject and it's always nice to have more power. Of course with that decision to get more usually means a heavier coach, lower gas mileage and more maintenance costs. Not saying it's good or bad just that IMHO these some of the results associated with a larger DP. I have a 450 on my 2016 Tiffin Phaeton 44OH which is 45' long. I tow a 2017 MKX which weighs in at about 4300 lbs. In my experience the last 3 years and putting on somewhere in the range of 10,000 miles per year mainly traveling from Florida back to Maine to summer visiting the family. I don't take the straightforward path up 95 instead I TAKE 77 to 81 then 78 287 etc., to Wells Maine. We take some very steep climbs throughout the trip especially up in Va. and Pa. going to particular CGs we prefer then once up in NE we do move around some through Maine and NH during our 3 months up there. Is it as hilly where you live I don't know but what I can say is my MH has no issues climbing these steep grades. I do have to say is you have to learn how to drive the MH to Maximize your HP/Torque to assure a steady climb to minimize your loss of speed. You need to learn when to pull over into climbing behind truckers and when not to. Lots of times if heavy traffic you'll have no choice hence why I go the way I do. Others with more experience with the two size engines would be a better means of comparison. I do know my MH has 10,000 towing capacity with my size coach with the 450. I know others with a 450 has a 15,000 towing capacity while the larger 605HP have upwards of 20,000 lbs. towing capacity. If I moved up to say a Cornerstone with 605 I'm sure I wouldn't complain. JMO

[EyezOpen]

Oops hammer hands this morning.

[youracman]

To the OP: All normally aspirated engines (like my Ford V-10) lose approximately 3% of their HP for each 1000 ft of elevation above sea level. So my previous rig had 305 HP (at about 4000 rpm or so) at sea level; going over Monarch pass here in CO it had 235HP ..... ouch. DPs have turbos to cram air into their engines ..... mountains aren't so much of a big deal.

With a gasser, you will get to camp a bit later than the DP's if a lot of mtn travel is involved .... but you will get there.

As you may have read, almost all seasoned RVers say that floor plan tops about every other selection criterion ...... assuming build quality is "OK."

Good luck in your search; good times and safe travels to ya.

[EyezOpen]

This can always be a interesting conversation until it hurts. Speaking for myself I keep it simple.

Tourqe is how much one can pull.

Horse power is how fast it can pull.

One will quickly notice big tourqe and low horsepower is quite affordable. Follow that with big tourqe and high horsepower it can be eye opening....Luxury has a price, most Class A's leave gas engines behind at 35', then there are tag axles...lol have fun!

Horse power is how fast you moved the wall.

Tourqe is how far you moved the wall.

[Flyer15015]

Funny that Ed mentions Monarch Pass (11+K').
I pull it twice a year hauling an 8K+# 24 ' enclosed car hauler from Buena Vista with the '31 Chrysler inside.
We make the Gunnison and Montrose car shows each summer.
Old jezebel with that bulletproof 8.1 gasser does not like it but she does it.
Click the 2 pancake fans on at the base and just chug our way up.
We do watch the chipmunks out run us though.

Mike in Colorado

[Arch Hoagland]

We go from Brigham City to Logan on 89 pulling a 4.000lb toad every year. That's a pretty good climb as you probably know.

Our gas 8.1 engine does fine although we do get slowed down a bit.

[Ray,IN]

Like #6 and #7 said; the general ratio is 1-100, but whatever you actually have gets you to the finish line, but it's not a race to the finish line.