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Horsepower for towing

Yahoo Message Number: 37441
I met with Caterpillar yesterday and received a surprise. Based on their guide, it appears the 525 Cat engine in the Country Coach Intrigue will not pull the coach easily up a 6% grade reducing speed to 40 mph with the engine fan on at 1800 RPM with a total load of 52,000 pounds. Needless to say the total coach rating of 61,000 pounds would become a sled.

Our primary focus is the ability of our new Country Coach Intrigue to tow our horses easily. This does not appear to be the case. The information in the Performance Guide from Cat dated 2005 showed an alarming calculation for a 52,500 pound motor home using a C13 Cat diesel rated at 525 horsepower with 1650 lb-ft of torque. The comment in the guide was: while the engine delivers 525 horsepower at 1800 rpm, the available wheel horsepower is reduced to 462 horsepower (engine cooling fan off) due to the total power train parasitic losses. Approximately 88% of the engine horsepower is available to do work at the drive tires. Based on calculations, the coach can be expected to climb a 6% grade at 45 MPH with the engine is turning at 1800 rpm. It is important to note the engine cooling fan can reduce the engine horsepower available at the drive wheels by 50 horsepower. With the engine cooling fan "ON", the coach is expected to climb the same 6% grade at 40 MPH since the available horsepower is reduced to 412 HP at 1800 RPM.

The key questions are: Do we have a material problem towing up a 6% grade like the Grapevine towards LA or Horseshoe Bend hill out of Boise, Idaho. Do we really need a 600 or 650 engine instead of 500/525 HP. Is a Cummings better or worse than the Cat.? Can we get a 600 HP engine in the Intrigue?


Re: Horsepower for towing

Reply #2
Yahoo Message Number: 37445
Vicki, I have a freightliner FL 60 crewcab with a 275 cat. I know its not a motorhome but I am pulling a 50' racecar trailer and I purchased it because I thought it would pull the trailer better than my F350 Ford Crewcab Dually. The Freightliner want hardly pull the hills here in Oklahoma unless I put it on the floor going down the hill. My F350 pulls it alot better except it is hell with crosswinds and then you have the beast pushing you and the brakes are not as good as the Freightliner. I wish I had of had someone explain all the losses to me as someone did to you. Then I could have understood why it didn't have enough hp or torque to pull. They did explain how to push the mode button on the gear selector to hold it in gear longer and help the pulling. Roger

Re: Horsepower for towing

Reply #3
Yahoo Message Number: 37446
Driving the grapvine and the cajon on a regular basis you are more likedly to be slowed down to 40 or 45 due to traffic and then it's a matter of how important it is to you to do whatever speed you're tryign to achieve. After all it's only for a few miles.

BTW, we have a 40' 06 allure 400 cummin isl pulling a toad (~4,000 lb) and in the summer with the a/c on if we start at the bottom of the cajon pass at 60, cruise on if NO traffic slowdowns then we'll still be at 55 by the time we reach the peak.

Quote from: Don Seager
Interesting info but one question comes to mind. How fast do you
want to climb a 6% grade? It would seem that a size engine necessary to meet your requirements could be easily calculated. For instance even the 650 Cat may not make it considering that additional HP also adds weight to the coach. Did Cat say that the 650 would work?

Quote
>

It would seem unlikely that one could change out a 525 in the
intrigue for a 650 without some very expensive renovations.
Everything in the drive chain has to be able to take the increased torque. Putting it in initially could also increase the coast above what CC believes to be the marketable price point for the Intrigue.

Quote
>

An least you start an email war here don't ask the question is
Cat better/worse than Cummins. (Just joking). There are minor differences but in the same HP range it is not going to make a significant difference.

Quote
>

BTW we sign our post here with Name, Coach Model, Year and CC
Coach number. It helps others in discussing your issues.

Quote
>

Don Seager

2004 Allure 31046

I met with Caterpillar yesterday and received a surprise. Based

on

Quote
their guide, it appears the 525 Cat engine in the Country Coach > Intrigue will not pull the coach easily up a 6% grade reducing

speed

Quote
to 40 mph with the engine fan on at 1800 RPM with a total load of > 52,000 pounds. Needless to say the total coach rating of 61,000 > pounds would become a sled.

Our primary focus is the ability of our new Country Coach

Intrigue

Quote
to tow our horses easily. This does not appear to be the case.

The

Quote
information in the Performance Guide from Cat dated 2005 showed

an

Quote
alarming calculation for a 52,500 pound motor home using a C13

Cat

Quote
diesel rated at 525 horsepower with 1650 lb-ft of torque. The > comment in the guide was: while the engine delivers 525

horsepower

Quote
at 1800 rpm, the available wheel horsepower is reduced to 462 > horsepower (engine cooling fan off) due to the total power train > parasitic losses. Approximately 88% of the engine horsepower is > available to do work at the drive tires. Based on calculations,

the

Quote
coach can be expected to climb a 6% grade at 45 MPH with the

engine

Quote
is turning at 1800 rpm. It is important to note the engine

cooling

Quote
fan can reduce the engine horsepower available at the drive

wheels

Quote
by 50 horsepower. With the engine cooling fan "ON", the coach is > expected to climb the same 6% grade at 40 MPH since the available > horsepower is reduced to 412 HP at 1800 RPM.

The key questions are: Do we have a material problem towing up a

6%

Quote
grade like the Grapevine towards LA or Horseshoe Bend hill out of > Boise, Idaho. Do we really need a 600 or 650 engine instead of > 500/525 HP. Is a Cummings better or worse than the Cat.? Can we

get

Re: Horsepower for towing

Reply #4
Yahoo Message Number: 37451
I remember reading somewhere that to manually shift before the base of a large hill to get your rpms up will result in better climbing speed and cooler temps. I know it does help my little 36'/330hp 8.3 Cummings

ddtuttle

(aka Billy Byte, trusty hound)
2000 Allure #30443




Re: Horsepower for towing

Reply #5
Yahoo Message Number: 37457
I am going to be optimistic and ask a few questions. Do you know the wet weight of the model coach your thinking of? (Coach empty but tanks full). Then make an educated guess as to the weight of your supplies and you and add. Add the weight of the trailer and horses. What do you get? Then calculate the results. As long as you can hold 45 you will find your ahead of the heavy 18 wheelers on the Grape vine. But if you want 55 mph look for more torque. The big 625 Cat that is now in the Magna has a much flatter and higher torque curve than the 600 Cummins, but haven't seen the curve on the 650. So the Big Cat would be the choice and that means a Magna would be your choice. I drive an older Intrigue which is much lighter, total weight 44,000 lbs, with a Cummins 400, and I weigh out at 42,500 towing my toad car. And 47 to 50 is what I make on the Grape vine which is fine unless you get caught behind a rig at just the wrong speed. Then I just sit back and enjoy the few extra minutes to get to the top.
I look at it this way. I drive steep grades maybe 1 to 3% of the time going up and the few extra minutes that take are just part of the fun of getting there. Other owners of 04 and 05 Intrigues have either the C-12 at 505 or the C-13 at 525 and when I travel in their presence if I am on the ball and now the terrain I can keep up, but for brute strength they are in another league. But then I get 8+ mpg to their 6+. The Lexus that had the older C-15 were reported to be getting mileage in the high 5+ range. In any case you and I will get there. Another thing to think about is gearing and which gear you have selected. A Cat will almost perform as well in a higher gear and lower rpm as it will in a lower gear at a higher rpm. Cummins engines you have to wind up and that's been my experience with Isc, Isl, Isx engines to get that last 3 or 4 mph, if that's really necessary.
TWI 2004 Intrigue 11731.

their guide, it appears the 525 Cat engine in the Country Coach Intrigue will not pull the coach easily up a 6% grade reducing speed to 40 mph with the engine fan on at 1800 RPM with a total load of 52,000 pounds. Needless to say the total coach rating of 61,000 pounds would become a sled.

Our primary focus is the ability of our new Country Coach Intrigue to tow our horses easily. This does not appear to be the case. The information in the Performance Guide from Cat dated 2005 showed an alarming calculation for a 52,500 pound motor home using a C13 Cat diesel rated at 525 horsepower with 1650 lb-ft of torque. The comment in the guide was: while the engine delivers 525 horsepower at 1800 rpm, the available wheel horsepower is reduced to 462 horsepower (engine cooling fan off) due to the total power train parasitic losses. Approximately 88% of the engine horsepower is available to do work at the drive tires. Based on calculations, the coach can be expected to climb a 6% grade at 45 MPH with the engine is turning at 1800 rpm. It is important to note the engine cooling fan can reduce the engine horsepower available at the drive wheels by 50 horsepower. With the engine cooling fan "ON", the coach is expected to climb the same 6% grade at 40 MPH since the available horsepower is reduced to 412 HP at 1800 RPM.

The key questions are: Do we have a material problem towing up a 6% grade like the Grapevine towards LA or Horseshoe Bend hill out of Boise, Idaho. Do we really need a 600 or 650 engine instead of 500/525 HP. Is a Cummings better or worse than the Cat.? Can we get a 600 HP engine in the Intrigue?

Re: Horsepower for towing

Reply #6
Yahoo Message Number: 37460
Vicki,

You have a lot of numbers on paper there. I am not sure exactly what your loaded coach weighs plus your horses and trailer. I assume that it is 52,000? I can only tell you that I have a 2002 Magna with just a C12 CAT rated at 425 HP and 1560 torque. Loaded it weighs about 41,000. I tow a 8,000lb Excursion behind it and I have no problem going up a 6% grade at well over 40MPH in 100 degree heat with no overheating problems whatsoever, engine or trans, as long as I hit the grade at 60 or above and keep the revs up. I pass semis regularly under these circumstances. Sure, the engine is working fairly hard at those limited times, but that is what they were built to do! So I do not know what you mean about "easily" but I would be amazed if a C-15 in the real world could not pull your coach and load with ease up such a grade. If you mean are you going to scoot up such long grades at 65 MPH, probably not!
Rich

Magna 6148

Quote from: VICKI
I met with Caterpillar yesterday and received a surprise. Based on > their guide, it appears the 525 Cat engine in the Country Coach > Intrigue will not pull the coach easily up a 6% grade reducing

speed

Re: Horsepower for towing

Reply #7
Yahoo Message Number: 37488
Thanks for the information. I think the coach will weigh around the 52,000 mark fully loaded. The coach has not been purchased as yet and as this is a sizeable investment, I don't want to make a mistake. I am also finding that I can't pull a trailer in California that is over 20' if I have a 45 foot motorhome. Have any of you had any experience with this?

--

- In Country-Coach-Owners@yahoogroups.com, "intrepid008" wrote:

Quote
Vicki,

You have a lot of numbers on paper there. I am not sure exactly

what

Quote
your loaded coach weighs plus your horses and trailer. I assume

that

Quote
it is 52,000? I can only tell you that I have a 2002 Magna with

just

Quote
a C12 CAT rated at 425 HP and 1560 torque. Loaded it weighs about > 41,000. I tow a 8,000lb Excursion behind it and I have no problem > going up a 6% grade at well over 40MPH in 100 degree heat with no > overheating problems whatsoever, engine or trans, as long as I hit > the grade at 60 or above and keep the revs up. I pass semis

regularly

Quote
under these circumstances. Sure, the engine is working fairly hard

at

Quote
those limited times, but that is what they were built to do! So I

do

Quote
not know what you mean about "easily" but I would be amazed if a C-

15

Quote
in the real world could not pull your coach and load with ease up > such a grade. If you mean are you going to scoot up such long

grades

Quote
at 65 MPH, probably not! >

Rich

Magna 6148

[quote author=VICKI"

>

> I met with Caterpillar yesterday and received a surprise. Based

on

Quote
their guide, it appears the 525 Cat engine in the Country Coach > > Intrigue will not pull the coach easily up a 6% grade reducing > speed

> to 40 mph with the engine fan on at 1800 RPM with a total load

of

Quote
52,000 pounds. Needless to say the total coach rating of 61,000 > > pounds would become a sled.
>
>
>

> Our primary focus is the ability of our new Country Coach

Intrigue

Quote
to tow our horses easily. This does not appear to be the case.

The

Quote
information in the Performance Guide from Cat dated 2005 showed

an

Quote
alarming calculation for a 52,500 pound motor home using a C13

Cat

Quote
diesel rated at 525 horsepower with 1650 lb-ft of torque. The > > comment in the guide was: while the engine delivers 525

horsepower

Quote
at 1800 rpm, the available wheel horsepower is reduced to 462 > > horsepower (engine cooling fan off) due to the total power train > > parasitic losses. Approximately 88% of the engine horsepower is > > available to do work at the drive tires. Based on calculations,

the

Quote
coach can be expected to climb a 6% grade at 45 MPH with the

engine

Quote
is turning at 1800 rpm. It is important to note the engine

cooling

Quote
fan can reduce the engine horsepower available at the drive

wheels

Quote
by 50 horsepower. With the engine cooling fan "ON", the coach is > > expected to climb the same 6% grade at 40 MPH since the

available

Quote
horsepower is reduced to 412 HP at 1800 RPM.
>
>
>

> The key questions are: Do we have a material problem towing up a

6%

Quote
grade like the Grapevine towards LA or Horseshoe Bend hill out

of

Quote
Boise, Idaho. Do we really need a 600 or 650 engine instead of > > 500/525 HP. Is a Cummings better or worse than the Cat.? Can we

get


Re: Horsepower for towing

Reply #9
Yahoo Message Number: 37492
As long as you are 65 feet or under combined you are fine. As far as your horsepower issues: Where do you get a loaded weight of $52,000 lbs.? At least according to the CC website the GVWR of an Inspire is 47,6000. That means fully loaded and this is way above the UVW which is not listed. On my coach the GVWR is almost 8,000 pounds above the UVW. That is a lot of stuff (even deducting water and fuel). Unless you have mostly rocks for your possessions, you will not come close to GVWR loaded. This will leave plenty for your horses without exceeding engine horsepower or GCWR. I suggest you call CC support and ask for Herb or Zack to get the right answer.

Rich

2002 Magna 6148

Quote from: VICKI
Thanks for the information. I think the coach will weigh around

the

Quote
52,000 mark fully loaded. The coach has not been purchased as yet > and as this is a sizeable investment, I don't want to make a > mistake. I am also finding that I can't pull a trailer in > California that is over 20' if I have a 45 foot motorhome. Have

any

Quote
of you had any experience with this? >
--

> - In Country-Coach-Owners@yahoogroups.com, "intrepid008" > wrote:
>

> Vicki,
>

> You have a lot of numbers on paper there. I am not sure exactly > what

> your loaded coach weighs plus your horses and trailer. I assume > that

> it is 52,000? I can only tell you that I have a 2002 Magna with > just

> a C12 CAT rated at 425 HP and 1560 torque. Loaded it weighs about > > 41,000. I tow a 8,000lb Excursion behind it and I have no problem > > going up a 6% grade at well over 40MPH in 100 degree heat with no > > overheating problems whatsoever, engine or trans, as long as I

hit

Quote
the grade at 60 or above and keep the revs up. I pass semis > regularly

> under these circumstances. Sure, the engine is working fairly hard > at

> those limited times, but that is what they were built to do! So I > do

> not know what you mean about "easily" but I would be amazed if a

C-

Quote
15

> in the real world could not pull your coach and load with ease up > > such a grade. If you mean are you going to scoot up such long > grades

> at 65 MPH, probably not!
>

> Rich

> Magna 6148
>
>

[quote author=VICKI"
>]
> >

> > I met with Caterpillar yesterday and received a surprise. Based > on

> > their guide, it appears the 525 Cat engine in the Country Coach > > > Intrigue will not pull the coach easily up a 6% grade reducing > > speed

> > to 40 mph with the engine fan on at 1800 RPM with a total load > of

> > 52,000 pounds. Needless to say the total coach rating of 61,000 > > > pounds would become a sled.
> >
> >
> >

> > Our primary focus is the ability of our new Country Coach > Intrigue

> > to tow our horses easily. This does not appear to be the case.
The

> > information in the Performance Guide from Cat dated 2005 showed > an

> > alarming calculation for a 52,500 pound motor home using a C13 > Cat

> > diesel rated at 525 horsepower with 1650 lb-ft of torque. The > > > comment in the guide was: while the engine delivers 525 > horsepower

> > at 1800 rpm, the available wheel horsepower is reduced to 462 > > > horsepower (engine cooling fan off) due to the total power

train

Quote
> parasitic losses. Approximately 88% of the engine horsepower is > > > available to do work at the drive tires. Based on calculations, > the

> > coach can be expected to climb a 6% grade at 45 MPH with the > engine

> > is turning at 1800 rpm. It is important to note the engine > cooling

> > fan can reduce the engine horsepower available at the drive > wheels

> > by 50 horsepower. With the engine cooling fan "ON", the coach

is

Quote
> expected to climb the same 6% grade at 40 MPH since the > available

> > horsepower is reduced to 412 HP at 1800 RPM.
> >
> >
> >

> > The key questions are: Do we have a material problem towing up

a

Re: Horsepower for towing

Reply #10
Yahoo Message Number: 37497
Hi

Actually, California has a 65' overall length limit. Most trailers are rates in length not including hitch and tongue... So you can only really pull about a 15' trailer, with the tongue that makes about 15 feet it...

Mikee

Re: Horsepower for towing

Reply #11
Yahoo Message Number: 37502
Unless you have connections with NASCAR or the NHRA, that is very true. When talking to some of the team bus drivers I understand Congress gave them special wavers, if they were team members in some way, or an official.
TWI 2004 Intrigue 11731 Did you get my note about Intrigues weighing 47,600 max?

Re: Horsepower for towing

Reply #12
Yahoo Message Number: 37504
Most states regulate length at 65 feet maximum and don't forget that is RV, tongue of trailer and trailer.

Re: Horsepower for towing

Reply #13
Yahoo Message Number: 37523
Before you even consider doing anything like pulling a trailer full of horses, you need to know the weight of the trailer and horses. You can't guess or say I think. There are a lot of people taking coaches to the limits and above, but that does not make it right or safe. Other items that will enter into the equation are the tire limits and speed. I would worry more about the tires, braking system and trailer hitch, not the engine and whether I can pull a hill at 65 mph.

Bill G. 2005 Magna #6425


Create a Home Theater Like the Pros. Watch the video on AOL Home.

Re: Horsepower for towing

Reply #14
Yahoo Message Number: 37557
Vicki - Horsepower is needed to run flat land and maintain speed - engine torque is needed to climb grades - increasing hp will not help you with grades unless torque is also increased. Gearing can also be a large factor, but the real question is are you capabable of handling a 65 foot rig in normal city driving conditions?

Freeway & Interstate straight line driving is one thing - but once you get off the Interstate you need to be able to safely manuver this "65 ft. rig" around in close areas in towns and into/out of show sights. Keep that in mind.

IMHO 500hp is more than you need, 400 would do the job, just not as fast but it is not realistic to expect a combined GVWR at 70,000# plus to run up a 6% grade at 60 mph, semi truck/trailers don't climb that fast unless empty, and they have 13+ gear selections to work with, you have 6. Getting you and your horse cargo there safe should be your biggest and primary concern. I would recommend that you leave a little earlier take your time and enjoy the trip.

Good luck with what ever you decide to purchase. :)

Mark P

03 Allure #30916

Quote from: VICKI
I met with Caterpillar yesterday and received a surprise. Based on > their guide, it appears the 525 Cat engine in the Country Coach > Intrigue will not pull the coach easily up a 6% grade reducing

speed