v10 torque vrs diesel

[tres_perros]

Hello folks

I have been looking for a used class A leaning towards a diesel as I plan on towing a Jeep and travel west coast, rockies

Evidentially I am told that the newer V10 fords have very similar torque range ( a model change with an extra valve)

So Id love to hear some opinions regarding this, including if maintenance/warranty contracts are any cheaper...

Thanks ahead of time! This is a great forum and has been very helpful

Keith

[RVpullinGuy]

427435 wrote:

uncleluap wrote:

ed1 wrote:
As an engineer (retired) I'm always amused by the arguments over diesel vs gas torque. The interesting part is that your diesel, generating 800 ft lbs at 1500 RPM, is exactly equivalent to your gasser generating 400 ft lbs at 3000 RPM. Why? Because both engines drive the same size wheels but at different engine speeds, so the gasser has a final gear ratio which is 2X that of the diesel. Guess what the 2:1 gear ratio does?- it multiplies the gasser's engine torque by a factor of 2. So, at the rear wheels, both engines provide the SAME torque.
now to be fair, the diesel is humming in the rear of the coach, while the gas engine is roaring under your feet.

This discussion always reminds me of the specifications for the M1A1 Abrams tank. 135,000 lbs, top speed of 60 mph, able to climb 45% slopes! And all with 270 ft lbs of torque!

How do they do that? They generate the torque at 30,000 RPM, then feed it into a 10:1 reduction gear. So then you've got 2700 ft lbs and 1500 HP at 3000 RPM.

I seriously doubt you are correct on your figures however your never going to see a ford V10 in 40ft 4 slide pusher style Motorhome
The reason being is a V10 ford gas engine does not produce enough torque at any RPM to move 36K+ up hills etc at any where near accepted level,s of speeds and reliability

Again, it's not the torque but the hp (and enough gears) that actually move a MH uphill.

The reason you don't see gassers in bigger MH's is that the people with the money for a 40' MH are also willing to pay the money for an air-ride suspension system and to have the engine/transmission in the back (quieter).

What you said is simply wrong about torque and HP. Anyone reading this should just apply real life logic and fact to understand why ALL bigger rigs have diesel motors with much higher torque. They can handle heavier loads and move them up hills better because of their higher torque.

[willald]

crappie_fisherman wrote:
...I've driven a 2 valve V10 pulling a 9000# TT (i.e. 17,000#'s combined) all over and I mean ALL over this beautiful country...didn't find any hill that I couldn't climb...did I slow down...sure...did I expect to...sure...

I now drive a 30,000#+++ 4000# toad Class-A with a diesel...in the few trips we've taken since getting it...the 6 speed Allison transmission sure is nice to have...if I had a 6 speed tranny behind my 2V V10...I'm sure that experience would have been easier on me as a driver...driving the 2V V10 loaded to 17,000#'s took driver control and attention to the road and the upcoming road/hills...

Thus far I've found I can simply set the cruise on the coach and the trans has yet to downshift out of 6th...on the SAME roads my V10 would downshift out of 4th...I KNOW that when we head to real hills...I'll use more gears on the coach...but comparing same roads to same roads...the Cat and Ally combo handles them much easier even though were more than twice the overall weight (coach and toad)...HP wise...my 2V V10 had 325HP...my Cat has 350HP...

Hehehe, and just to keep the 'fun' going, Joe:

..Your V10 in the Ex was putting about 220 of its 310 HP actually to the wheels most of the time (cruising down the highway, turning maybe 3000 RPM at 65-70mph). Same as mine was.

However, your Cat is putting about 300 horsepower to the wheels most of the time (cruising down the highway, turning maybe 2000 RPM or so).

Soooo, bottom line is the diesel is able to put more actual horsepower to the ground than the V10 during everyday driving, even though the peak torque rating of the gasser may in some cases be higher (like on the newer 362 HP V10s). Hence the reason it can stay in 6th gear and feels so much more powerful (and it ##$% sure ought to, for how much more $$ it costs compared to a gasser V10!!!)

Had your V10 been geared different so that it too was putting 300 horsepower to the ground like your Cat does, and you didn't mind it (V10) turning 4500 rpm or whatever all day to put out that much horsepower....The V10 too, would have stayed in one gear and rarely downshifted just like your Cat does now. But you wouldn't have liked hearing it turn that fast all the time, haha.

(Disclaimer: All numbers above are rough guesses, and are only used to illustrate the point on how gassers and diesels power/torque curve are different. )

Anyway, I think these discussions go on and on, due to the fact many just don't truly grasp the definition, etc. of torque and horsepower, and don't understand why a diesel thats rated for less peak horsepower than a gasser can feel so much more powerful. Add that to the fact that so many folks on internet forums insist on proving to everyone that they're right and the other guy is wrong...Wellll, you end up with a bunch of 13 page discusssions on this topic, hahaha. 🙂

It *IS* fun and entertaining to read, though, regardless. 🙂

[Cloud_Dancer]

If I had been satisfied with a gasoline motorhome, I could've saved me significant monies. Experienced taught me that traveling in your own airplane is NOT as convenient and comfortable as going in your own big diesel pusher(and bringing along your own SUV).
But, "each one to their own poison".

[crappie_fisherm]

It's funny how these Gas V. Diesel threads NEVER seem to end...LOL...

It truly is akin to Hensley or not, chevy V ford V dodge, fridge on or off while driving, etc, etc, etc...LOL

I've driven a 2 valve V10 pulling a 9000# TT (i.e. 17,000#'s combined) all over and I mean ALL over this beautiful country...didn't find any hill that I couldn't climb...did I slow down...sure...did I expect to...sure...

I now drive a 30,000#+++ 4000# toad Class-A with a diesel...in the few trips we've taken since getting it...the 6 speed Allison transmission sure is nice to have...if I had a 6 speed tranny behind my 2V V10...I'm sure that experience would have been easier on me as a driver...driving the 2V V10 loaded to 17,000#'s took driver control and attention to the road and the upcoming road/hills...

Thus far I've found I can simply set the cruise on the coach and the trans has yet to downshift out of 6th...on the SAME roads my V10 would downshift out of 4th...I KNOW that when we head to real hills...I'll use more gears on the coach...but comparing same roads to same roads...the Cat and Ally combo handles them much easier even though were more than twice the overall weight (coach and toad)...HP wise...my 2V V10 had 325HP...my Cat has 350HP...

Joe.

[michelb]

427435 wrote:

michelb wrote:

427435 wrote:
...
Again, a 300 hp diesel engine won't climb a hill faster than a 300 hp gas engine moving the same load----------at least at altitudes under 3000 ft. Turbocharged engines (gas or diesel) do have advantages at higher altitudes.

The small gas engine is not irrelevant------------it serves to prove the point about the differences between hp and torque.

I would strongly disagree with this. Our 275HP (might even be 325HP) gasser will not keep up with a 300HP ISB, ISC or CAT 3126E.

Our old 98 Pace Arrow 36B gasser weighs about 20k lbs on the road and is MUCH slower climbing hills than in our 03 Phaeton DP (330HP) even with the DP pulling a toad on a dolly (total weight easily over 30k lbs).

I'm not saying that everyone needs to buy a diesel as the gas engine will get you over the hill and it does what it needs to do but there's a huge difference between a gas engine with 300HP/400 ft.lbs torque and a diesel with 300HP/600 ft. lbs or even 900 ft. lbs of torque.

I suspect you weren't willing to run your gasser at 4000 rpm when climbing a hill. I'll routinely hold my V10 at 4000 to 4500 rpm when climbing hills. Works great.

FWIW, I'm sure I had pedal to the floor and let it climb as fast as it could (which on some inclines was probably 15-20 mph by the time we got to the top).

It's possible that the engine needed a tune-up (although it seems to run fine).

I'm just comparing my personal experience with a 98 PaceArrow 36B (Chev 454 Vortec - roughly 20k lbs on the road) and with a 03 Tiffin Phaeton 40RH (CAT 7.2 - roughly 31k lbs with dolly and toad). Both engines have roughly the same HP but there's a huge avantage in climbing in the DP even though the DP is more than 50% heavier on the road. As someone else mentioned, the 6 speed Allison on the DP vs transmission on the gasser could be a significant part of the difference.

[RayChez]

Horse power is for speed, torque at the wheel is for power. Diesel over gasoline by a long shot. No comparison!

[bmacz06]

This thread is GREAT! I have been stuck at the airport for several hours and needed to kill some time and this thread was just the ticket. I read every post and found it highly entertaining.

I decided on a a new gasser due to the substantial savings over a diesel. I will have no problem slapping the peddle to the floor and keeping it there all the way up the mountain. All of these engines, not limited to diesel, will last longer than most people think and could very well outlive the motorhome itself.

I do find it interesting the most gas motorhomes are limited to towing 5000 pounds but when you look at the Ford website the F-53 chassis is rated up to 6000 or 6500 depending on wheelbase and GVWR.

[DanTheRVMan]

427435 wrote:

michelb wrote:

427435 wrote:
...
Again, a 300 hp diesel engine won't climb a hill faster than a 300 hp gas engine moving the same load----------at least at altitudes under 3000 ft. Turbocharged engines (gas or diesel) do have advantages at higher altitudes.

The small gas engine is not irrelevant------------it serves to prove the point about the differences between hp and torque.

I would strongly disagree with this. Our 275HP (might even be 325HP) gasser will not keep up with a 300HP ISB, ISC or CAT 3126E.

Our old 98 Pace Arrow 36B gasser weighs about 20k lbs on the road and is MUCH slower climbing hills than in our 03 Phaeton DP (330HP) even with the DP pulling a toad on a dolly (total weight easily over 30k lbs).

I'm not saying that everyone needs to buy a diesel as the gas engine will get you over the hill and it does what it needs to do but there's a huge difference between a gas engine with 300HP/400 ft.lbs torque and a diesel with 300HP/600 ft. lbs or even 900 ft. lbs of torque.

I suspect you weren't willing to run your gasser at 4000 rpm when climbing a hill. I'll routinely hold my V10 at 4000 to 4500 rpm when climbing hills. Works great.

It could be driver inexperience or it could be need of a tune up? spark plugs? or more complicated issues on his 98 gasser.

I and the Cat engineers can insure you that speed up hill is a function of weight/HP

http://www.catrvclub.org/PDF_Docs/Understanding_Perf.pdf

My lower torque isb passing higher torque MHs up hill and even smaller torque gassers passing both of us is consistent with this.

[willald]

VinCee wrote:
If the money equation (aka what can I/you afford?) was not one of the prime deciding factors, I would think 80% or more of class A's on the road would be DP's. However, most of us have to deal with the reality that $$$$$ doesn't grow on trees.

VinCee, that 80% may well be true, if money were not in the equation. However, I think there'd always be some demand for gasser MHs, from people like me that simply want nothing to do with a DP (regardless of $$) because:

1. I HATE having the door at very front, in front of passenger seat. It makes one feel like they're driving a big greyhound or school bus (LOL, every time I see one, I look for the stop arm and red blinking lights to come on). Not to mention how wierd it looks for passenger seat to be further back than driver seat.

2. I really, really like having a window on rear wall in back of MH (bedroom). I've yet to ever see any DP that has ever offered this.

3. I don't want a rig that requires service techs to march back and forth in the coach to the back bedroom, to get access to the engine for service.

4. Diesels just plain STINK, and they are LOUD. Diesels used in pickups have got much better in this regard in last few years, but big diesels in DP Motorhomes are just as loud and stinky as ever from what I've seen.

Anyway, I agree that this topic got waaay more techincal and went on much longer than the OP probably intended.

[VinCee]

Well I'ver read every post on this always counterversial subject. I must say I have really enjoyed the many technical posts on formulas and such. Each side basing their strong opinions on fact and science vs. plain old IMHO type stuff. Bravo to the engineers out there! However, the thread really got wayyy to technical from the OP's basic question. Sure he asked about towing power and such, hence the turning point of the thread. But, you would think there would be more imput from the every day joes out here in RV land such as myself, of the "other" reasons, besides floor plan, in chosing one type of rig over another. So, this is where I come in with "MHO"! I do not full time. I am for the most part a week end warrior with one or two long trips a camping season, somewhere between April to November in the north east. Or about 40 nights a year (how sad). For "ME" I could not justify a tremendously more expensive diesel rig over my 2011 Georgetown V10. Sure I could of bought an older diesel, trading age of my rig to get a darn nice used DP, but I still could not justify the higher operating costs and fuel to my yearly cost to own, operate and use with such limited use. Like most, I do dream of moving up to a DP, whether its heading to retirement, or circumstances change with DW and I and we can get more use and enjoyment out of the lifestyle. If the money equation (aka what can I/you afford?) was not one of the prime deciding factors, I would think 80% or more of class A's on the road would be DP's. However, most of us have to deal with the reality that $$$$$ doesn't grow on trees.
I am extremely happy with my V10 as it does everthing and more, at a modest investment, that DW and I ask or need from it.

[Sully2]

Cloud Dancer wrote:
My first MH was one of the original Winnebagos that had a Dodge engine/chassis. The next one had a Ford. Then, I had a couple with big-block GM engines/P-30. Then, another gasser, a nice Vectra on a F-53 chassis. I'm an ole gearhead/racer, and I am NOT opposed to WOT all the way up a hill.
NONE of my gassers could outclimb my present heavy DP which is on a Spartan/8.3 ISC Cummins.
My gassers all had 4 speed trannies, and it was obvious to me they would've done much better with a 6 speed, and even better with a 10 speed (there's a reason Newells have a 10 speed....:B)

AMEN to that. My P30's lacked proper gears in a BAD way...

[Cloud_Dancer]

My first MH was one of the original Winnebagos that had a Dodge engine/chassis. The next one had a Ford. Then, I had a couple with big-block GM engines/P-30. Then, another gasser, a nice Vectra on a F-53 chassis. I'm an ole gearhead/racer, and I am NOT opposed to WOT all the way up a hill.
NONE of my gassers could outclimb my present heavy DP which is on a Spartan/8.3 ISC Cummins.
My gassers all had 4 speed trannies, and it was obvious to me they would've done much better with a 6 speed, and even better with a 10 speed (there's a reason Newells have a 10 speed....:B)

[427435]

michelb wrote:

427435 wrote:
...
Again, a 300 hp diesel engine won't climb a hill faster than a 300 hp gas engine moving the same load----------at least at altitudes under 3000 ft. Turbocharged engines (gas or diesel) do have advantages at higher altitudes.

The small gas engine is not irrelevant------------it serves to prove the point about the differences between hp and torque.

I would strongly disagree with this. Our 275HP (might even be 325HP) gasser will not keep up with a 300HP ISB, ISC or CAT 3126E.

Our old 98 Pace Arrow 36B gasser weighs about 20k lbs on the road and is MUCH slower climbing hills than in our 03 Phaeton DP (330HP) even with the DP pulling a toad on a dolly (total weight easily over 30k lbs).

I'm not saying that everyone needs to buy a diesel as the gas engine will get you over the hill and it does what it needs to do but there's a huge difference between a gas engine with 300HP/400 ft.lbs torque and a diesel with 300HP/600 ft. lbs or even 900 ft. lbs of torque.

I suspect you weren't willing to run your gasser at 4000 rpm when climbing a hill. I'll routinely hold my V10 at 4000 to 4500 rpm when climbing hills. Works great.

[michelb]

427435 wrote:
...
Again, a 300 hp diesel engine won't climb a hill faster than a 300 hp gas engine moving the same load----------at least at altitudes under 3000 ft. Turbocharged engines (gas or diesel) do have advantages at higher altitudes.

The small gas engine is not irrelevant------------it serves to prove the point about the differences between hp and torque.

I would strongly disagree with this. Our 275HP (might even be 325HP) gasser will not keep up with a 300HP ISB, ISC or CAT 3126E.

Our old 98 Pace Arrow 36B gasser weighs about 20k lbs on the road and is MUCH slower climbing hills than in our 03 Phaeton DP (330HP) even with the DP pulling a toad on a dolly (total weight easily over 30k lbs).

I'm not saying that everyone needs to buy a diesel as the gas engine will get you over the hill and it does what it needs to do but there's a huge difference between a gas engine with 300HP/400 ft.lbs torque and a diesel with 300HP/600 ft. lbs or even 900 ft. lbs of torque.

[427435]

nevadanick wrote:
Correct me if i am wrong but i was to understand that torque is what moves you and horsepower is what you feel.

No. Torque is what turns the wheels. Hp determines how fast they turn.