Gas engine and Diesel of same specs.Pull the same.

bmanning wrote:
Not sure why you took my input personally; if you felt I was referring to your particular post, apologies, I wasn't.

As Hannibal stated, he wasn't actually disagreeing with you.

I do value the theoretical...

...I just value real-world experience, especially that which is being supplied by a respected forum member, equally if not moreso.

I agree with your last sentence above ^.

I guess I thought you were referring to my post because you quoted everything, including mine. It looked like a compare/contrast between ignorable "theory" responses and good experience responses. I've had people jump my case because "I couldn't possibly know without first hand experience" (which is flawed thinking IMHO). I can tell you with high certainty that it's not snowing in New York by looking up the temperature even though I'm miles from actually being there.

It's all good. :)

p.s. I wrote the post above this one before I saw your reply.

Hannibal wrote:
wnjj, I don't think I was disagreeing with you.

You're right. We do agree.

I was referring to the comment about ignoring responses that aren't based upon experience. The best information is usually a mix of "theory" (or rather facts) and experiences. Both must be taken with a grain of salt.

Too many times people's "experience" is from a 10 year old truck to a brand new one and they're convinced the fuel type made all of the difference. I'd say your comparative experience is about as close as it gets which, conicidentally lines up with my "theory".

wnjj wrote:

bmanning wrote:

Hannibal wrote:

wnjj wrote:

ib516 wrote:
The diesel will pull at lower rpm with much less transmission shifting. It will also get 50% better mpg towing or empty.

Lower rpm = lower road speed, unless you run in a higher gear which means lower torque at the wheel. You can't have it all unless you've got HP. I seriously doubt a stock 235hp diesel with similar torque to a 345hp gas engine would pull as well but I can't say I've had first hand experience. Modded is another story for either engine.

I have had that experience. My '05 345hp/365ftlb Hemi powered 2500HD towed our 10,400 lb 5th wheel faster up the grades than my '03 duplicate 250hp/460ftlb Cummins powered 2500HD. It was at 4500rpm vs 2900rpm, not 5k rpm vs 1800rpm. And we got 2mpg better with the Cummins. Not twice the mileage. A stock 8.1 would run circles around a stock '01 Cummins.

Hannibal speaks from real-world experience, not speculation or theory.

Seems easy to me to decide which responses to give weight to and which to ignore.

Facts are just as important as "experience". My first two sentences were facts. My second two were opinion based upon those facts and clearly marked as such. Some people find value in responses that are based upon more than potentially biased anecdotal experience, even if you don't.

Not sure why you took my input personally; if you felt I was referring to your particular post, apologies, I wasn't.

As Hannibal stated, he wasn't actually disagreeing with you.

I do value the theoretical...

...I just value real-world experience, especially that which is being supplied by a respected forum member, equally if not moreso.

well if were gonna start disecting stuff......what is the point of this thread. we all prefer different engines. why must we go on and on and on and on and on. topic has been covered. in the end diesel wins. :)

BenK wrote:

ramyankee wrote:
By my sig, i pull with a 2002 8.1.....Its specs are roughly 340HP and 455 lb ft of torque. If a guy were to opt for a 2000-2002 Cummins, approx the same specs, does a Diesel pull any easier. Just a thought.
I realize they tow at a much lower RPM.
Thanks. Just curious.

Too long and haven't read all of the responses...here is mine

You are comparing apples to oranges

First, one has more BTU's per equal volume measurement than the other
So not a level comparision

PSI on the piston top is the name of the game. One has a dialed in
or designed in higher compression ratio vs the other. One has more
potential energy via that higher BTU count and higher compression
ratio out of the box.

SMOG controls are different and makes a huge bite out of performance
Not all the time, but during 'their' working cycle periods

Most of today's diesel's in TV's are forced fed. Gassers are not
That is back to the PSI on the piston top again

There are a host of other attributes just for the ICE. Like valving
(multi, cam profile, push-rod vs OHC, etc)

Then the rest of the drive train. Most notable is the gearing all the
way to pavement and that includes tire rev's per mile

Bottom line is the biggie...one has more BTU's than the other and therefore
'should' have an advantage for your question

My 7.4L pulls as good as that era's diesel's, but they all get better
MPG because of their higher BTU's per gallon

btu's per gallon goes to the diesel which contributes to the diesel's better fuel economy but as far as which fuel can make more torque and power per displacement the winner is gasoline. Diesels outperform gasoline engines due to the fact they lend themselves more easily to turbocharging. Take the turbo off a diesel and you'll see how that more btu's per gallon doesn't put as much pressure on the piston as gadoline.

wnjj, I don't think I was disagreeing with you.

On vail pass, that 454 was down some 30% ion hp due to altitude! Along with the max a 454 was ever speced at was 295 in the 97-2000 years. So you had more hp to begin with! much less the altitude difference at 10K feet! My old 6.5td out pulled a 454 at 9K ft in yellowstone, with the SAME trailer, but total wt was 1000 lbs more! All because of the turbo on the diesel! yet it had 50 less hp. At sea level the 454 out did the 6.5 on a free way grade. But due to the auto behind the 454, a manual behind the 6.5, the low end, the 454 stalled out on 15-20% grades, where as the 6.5 kept going due to better gearing.

There is more than one way to skin a cat, and look at which rig will be the better one!

The army found, a turbine 2000hp motor with 400 lb ft of torque, would move a tank just as fast as a 2000hp diesel with 4000 lb ft of torque! BUT, one had to use a drive train that worked for the turbine, not a diesel type drive train. One has to do the same with gas vs diesel. other wise, which even has the correct drivetrain for its specs etc, will win the battle!

marty

marty

ramyankee wrote:
By my sig, i pull with a 2002 8.1.....Its specs are roughly 340HP and 455 lb ft of torque. If a guy were to opt for a 2000-2002 Cummins, approx the same specs, does a Diesel pull any easier. Just a thought.
I realize they tow at a much lower RPM.
Thanks. Just curious.

You will not find a 2000-2002 Cummins with those kinds of spec's. It will have a lot less L's,hp,tq. My 2004.5 5.9L 325hp,600tq. Cummins with 5er out pulled a 454 powered Chevy 3+3 Dually with a slide in camper on Vail pass a few years ago.

bmanning wrote:

Hannibal wrote:

wnjj wrote:

ib516 wrote:
The diesel will pull at lower rpm with much less transmission shifting. It will also get 50% better mpg towing or empty.

Lower rpm = lower road speed, unless you run in a higher gear which means lower torque at the wheel. You can't have it all unless you've got HP. I seriously doubt a stock 235hp diesel with similar torque to a 345hp gas engine would pull as well but I can't say I've had first hand experience. Modded is another story for either engine.

I have had that experience. My '05 345hp/365ftlb Hemi powered 2500HD towed our 10,400 lb 5th wheel faster up the grades than my '03 duplicate 250hp/460ftlb Cummins powered 2500HD. It was at 4500rpm vs 2900rpm, not 5k rpm vs 1800rpm. And we got 2mpg better with the Cummins. Not twice the mileage. A stock 8.1 would run circles around a stock '01 Cummins.

Hannibal speaks from real-world experience, not speculation or theory.

Seems easy to me to decide which responses to give weight to and which to ignore.

Facts are just as important as "experience". My first two sentences were facts. My second two were opinion based upon those facts and clearly marked as such. Some people find value in responses that are based upon more than potentially biased anecdotal experience, even if you don't.

ramyankee wrote:
By my sig, i pull with a 2002 8.1.....Its specs are roughly 340HP and 455 lb ft of torque. If a guy were to opt for a 2000-2002 Cummins, approx the same specs, does a Diesel pull any easier. Just a thought.
I realize they tow at a much lower RPM.
Thanks. Just curious.

Too long and haven't read all of the responses...here is mine

You are comparing apples to oranges

First, one has more BTU's per equal volume measurement than the other
So not a level comparision

PSI on the piston top is the name of the game. One has a dialed in
or designed in higher compression ratio vs the other. One has more
potential energy via that higher BTU count and higher compression
ratio out of the box.

SMOG controls are different and makes a huge bite out of performance
Not all the time, but during 'their' working cycle periods

Most of today's diesel's in TV's are forced fed. Gassers are not
That is back to the PSI on the piston top again

There are a host of other attributes just for the ICE. Like valving
(multi, cam profile, push-rod vs OHC, etc)

Then the rest of the drive train. Most notable is the gearing all the
way to pavement and that includes tire rev's per mile

Bottom line is the biggie...one has more BTU's than the other and therefore
'should' have an advantage for your question

My 7.4L pulls as good as that era's diesel's, but they all get better
MPG because of their higher BTU's per gallon