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Old 03-19-2014, 12:54 PM   #1
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Engines - How much is enough?

As a followup to a previous post on "Buying A MH Out Of State" I was also wondering about engine size. And yes, size does matter!!!!

Our plan is to purchase a 40' MH (Country Coach type 2007ish).

While I do understand that:
1. We need to drive the MH to determine on our own what we personally feel is sufficient
2. We live in the San Diego area and almost every direction we travel there are sizable hills/mountains to clime
3. We pull a 5,000 pound toad (no we do not want to purchase/replace with a lighter one)
4. We're not thrilled about struggling climbing up hills at 29 mph

We're asking for suggestions/opinions (yes everyone has one) from those with comparable and larger MH in like situations.

Comparisons will help to determine minimums.

We await your experienced replies.

2006 Monaco Signature 45' Commander IV ISX 600
2013 Avalanche toad
And a rather large and very hairy Bear for a traveling companion
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Old 03-19-2014, 01:04 PM   #2
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Our 2000 Newmar has a GVWR of 31,000 with a GCWR of 41,000. It has a stock Cummins 8.3, 350 HP with 6 speed and does all we need even towing our 2010 Accord.

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Old 03-19-2014, 01:07 PM   #3
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Currently at 1hp, per 100 lbs of GCWR. 1ftlb torque per 35 lbs GCVW.
It's not a rocket, but gets me every where I want to go.
Way faster up hills than a loaded semi.

If you find a coach in the 1 hp, per 85 lbs Of GCWR, you will spend more on fuel , but you should be very, very, happy with the performance.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
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Old 03-19-2014, 01:23 PM   #4
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Originally Posted by Skip426 View Post
Currently at 1hp, per 100 lbs of GCWR. 1ftlb torque per 35 lbs GCVW.
It's not a rocket, but gets me every where I want to go.
Way faster up hills than a loaded semi.

If you find a coach in the 1 hp, per 85 lbs Of GCWR, you will spend more on fuel , but you should be very, very, happy with the performance.
With 1 per 64lbs of GCWR and 1 per 23lbs on torque no wonder I am happy.
And I get very good fuel mileage.
1999 Trade Winds 7371 Cat 3126B w/current upgrades
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Old 03-19-2014, 01:37 PM   #5
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There's no such thing as too much power. Buy as much as you can afford (especially if you're not paying interest for the power). Probably need to look for a coach that has the upgraded engine, not the base unit.
Glenn & Mary
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Old 03-19-2014, 02:20 PM   #6
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You can have all the HP you want/can get, but the bottom line for pulling up hill is Torque! Gas engines just do not have the inherent torque that a diesel engine will have.
2012 Journey 40U (Our Incredible Journey)
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Old 03-19-2014, 02:26 PM   #7
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I have a 42' CC with a 425hp Cummins. It has plenty of power for me. Would the 500hp ISM be better? Sure but then I'd have to feed it.
'07 Country Coach Allure 470 Siskiyou Summit #31578, Cummins ISL 425; 2014 Ford F150 toad; Air Force One Toad Brake.
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Old 03-19-2014, 02:38 PM   #8
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No matter how big you have, someone will pass you, right at the midpoint of the biggest hill you ever went up. The limiting factor is how much torque the transmission will take. Buy something with 400 HP or more and you should be satisfied.
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Old 03-19-2014, 02:47 PM   #9
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If some is good, more is better, then too much is just right!

There is no such thing as having too much power on hand. I have a 350 hp Cat in my Alfa, and i realize its sufficient for my needs, but it doesn't stop me from wondering if I can't stick a 700 hp Cat and appropriate transmission between the framerails... That's the problem with being involved with drag racing... There is always a way to put something bigger in there!
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Old 03-19-2014, 02:54 PM   #10
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Look at torque not hp. I have 1250 ft. Lbs. in a tag axle at 44 feet. I've pulled a toad on a dolly up a 7% 4 mile grade in 6th gear at 55 mph without any issues and got 9.3 mpg for the entire 3000 mile trip.
1250 ft. lbs. should be all you need.
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Old 03-19-2014, 03:06 PM   #11
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I have the ISB-XT 360hp and 850 lb-ft of torque, I pull a 1/2 ton crew cab Chevy coach weighs 31,000 lbs loaded and had no problems through the Rockies last summer. I think the slowest that I got was about 35 going up to the Continental Divide outside of Butte, MT not sure the grade or length but it is long and steep. Also, I average 8.5 mpg and drive about 70 most of the time.
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Old 03-19-2014, 03:07 PM   #12
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My actual combined weight is just shy of 50,000 lbs when loaded. I have the Cummins ISX15 rated at 525HP and 1650 fpt. Recently in the Rockies climbing hills and more HP would have been nice. However, that is the only time I wish I had more. As for fuel economy, I drive about 70 mph plus most of the time, I get 6 to 7 mpg. My worst with a head wind was about 5.4 (driving about 60 mph) and my best with a tale wind was 9.1.

A 500 mile trip with head wind could cost you approx. 92 Gallons versus waiting for a tail wind and burning approx. 55 gallons. I usually have a head wind both ways is seems. I unfortunately can't afford the time to wait.
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Old 03-19-2014, 03:33 PM   #13
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HP keeps you at speed. TORQUE gets you to speed.

That is what i have been told.

Torque pulls you out of hole
HP keeps you out of hole

you want to go 65 up hill...? you need the HP to do this.
you want to go 0 to 60 in 10 seconds pulling 10k lbs? You need torque to do this

My old CAT / Allison big liter combo only optimized for 325 hp... so she struggles up hill pulling 6,000 lbs (45 mph or so).... but from 0 to 50?!?! ... her old school 1,225 foot lbs of torque pulls with the biggest detroits (or at least in the race)

My GCVW = 40,000 and i travel loaded up around that limit.
fkloster = Fritz, Erin, Sadie, Bo (& Lucy the Weim)
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Old 03-19-2014, 04:52 PM   #14
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truth be told i would be more happy going up a hill at 29 MPR and work with a few hills then over pay for gas on a bigger motor if all you have is a few hills befor going out of state to some where more less hilly then i would be more looking for the right size motor for the MPG you need .... i do not mind getting in line with the trucks going up hills and save 200$ on gas fro a big trip and really your going to wind up with a allison 3000 or 4000 pulling a big load in over drive well start to pop err codes so you well still find your self slowing down and going to lower gears... if you have alot of hills i do under stand but higher loads and bigger motors are setup for lower gearing and lower MPG

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