# Do you have what it takes? - HP vs. Torque



## 2COR517 (Oct 23, 2008)

I want to haul a big load up a hill quickly. Am I more concerned with Horsepower or Torque?


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## Stik208 (Oct 19, 2004)

I voted torque, tell me what I win at once.


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## cubicinches (Oct 19, 2008)

........


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## JohnnyU (Nov 21, 2002)

Horsepower is just torque per unit time, so they're both technically present here....

:laughing:


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## Triple L (Nov 1, 2005)

I've always heard, Torque gets it going, Horsepower keeps it going......................


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## CGM Inc. (Dec 15, 2008)

Up to approx. 5300 rpm you go on torque past that point HP will cross the torque curve. Any dyno chart looks like that. with our heavy trucks you want torque not HP.


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## cretebaby (Aug 23, 2008)

I think someone is fishing.


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## 2COR517 (Oct 23, 2008)

cretebaby;1022968 said:


> I think someone is fishing.


Not so much...

How did you vote


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## cretebaby (Aug 23, 2008)

2COR517;1022973 said:


> Not so much...
> 
> How did you vote


What was the question again? LOL

Are you starting from a dead stop?

I voted Torque.


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## 2COR517 (Oct 23, 2008)

Let's say you come into the grade at 50mph and want to maintain that speed.


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## cretebaby (Aug 23, 2008)

2COR517;1023003 said:


> Let's say you come into the grade at 50mph and want to maintain that speed.


Definitely torque then.


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## PTSolutions (Dec 8, 2007)

i vote boost!


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## mayhem (Aug 25, 2006)

Torque. Horsepower sells trucks, torque moves em.


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## leon (Nov 18, 2008)

*trucks*

Torque is my vote

I was always reminded you travel up the hill
the same speed you travel down it;
long before exhaust retarders and jake brakes 
using the gears to slow you down.
Too many people failed to heed that simple advvice and 
they died or killed people coming off our mountains here.

no arguments about what constitutes a mountain or a hill,
okay its lunch time and recess.

Its a nice algebra problem easy to work with.

:yow!::waving:

Its time for recess, can I go out side and dance the
hokey pokey with snoopy and woodstock and watch
woodstock drive the Zamboni across the bird bath now?

leon


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## cubicinches (Oct 19, 2008)

leon;1023298 said:


> I was always reminded you travel up the hill
> the same speed you travel down it;
> long before exhaust retarders and jake brakes
> using the gears to slow you down.
> ...


Soooo.... Uh, like, what's your vote?


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## buckwheat_la (Oct 11, 2009)

torque, definetly, as you start going up that hill, your load well act like a anchor, and you well need the torque to keep luging up,


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## jb1390 (Sep 23, 2008)

Horsepower is actually the correct answer. Torque AT THE WHEELS will define how fast you can accelerate up that hill. The trick is that torque measured at the flywheel has NOTHING to do with torque at the wheels, as it can be adjusted by gearing as much as you want. Power is defined as the speed at which work can be accomplished. Climbing the hill is work (work=force times distance) Torque is just a measure of force, only in a rotational axis instead of linearly. So kudos to the other 4 people that voted with me for horsepower......to those that incorrectly voted for torque, continue reading. 

The reason that torque is valuable for a truck is that no one likes revving the engine very high for towing or plowing. If your torque comes low in the powerband (diesel), this allows maximum acceleration at that low rpm. This is wonderful for towing at a consistent speed (which is not the same as "as fast as possible"). However, if you can apply 500 foot pounds of torque at 2000 rpms, and I can apply 250 foot pounds of torque at 8000 rpms, I can climb the hill at twice the speed of you. (neglecting air resistance, etc). I can gear my motor down by .5, doubling the force. Now I have 500 foot pounds too, going at 4000 rpms. Since you are only at 2000 rpms, I am going twice as fast as you with the same force. Then again, who would like to run their tow vehicle at those rpms? Nevermind fuel consumption. But horsepower is still what moves loads up hills quickly. Because horsepower tells you what SPEED at which you can apply your torque.


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## buckwheat_la (Oct 11, 2009)

jb1390;1023347 said:


> Horsepower is actually the correct answer. Torque AT THE WHEELS will define how fast you can accelerate up that hill. The trick is that torque measured at the flywheel has NOTHING to do with torque at the wheels, as it can be adjusted by gearing as much as you want. Power is defined as the speed at which work can be accomplished. Climbing the hill is work (work=force times distance) Torque is just a measure of force, only in a rotational axis instead of linearly. So kudos to the other 4 people that voted with me for horsepower......to those that incorrectly voted for torque, continue reading.
> 
> The reason that torque is valuable for a truck is that no one likes revving the engine very high for towing or plowing. If your torque comes low in the powerband (diesel), this allows maximum acceleration at that low rpm. This is wonderful for towing at a consistent speed (which is not the same as "as fast as possible"). However, if you can apply 500 foot pounds of torque at 2000 rpms, and I can apply 250 foot pounds of torque at 8000 rpms, I can climb the hill at twice the speed of you. (neglecting air resistance, etc). I can gear my motor down by .5, doubling the force. Now I have 500 foot pounds too, going at 4000 rpms. Since you are only at 2000 rpms, I am going twice as fast as you with the same force. Then again, who would like to run their tow vehicle at those rpms? Nevermind fuel consumption. But horsepower is still what moves loads up hills quickly. Because horsepower tells you what SPEED at which you can apply your torque.


ok then, i have a question, if what you say is true (and i am not calling you a liar) why is it that a 8.1 chev gas, has similar hp as the diesel in a 03, (if i remember correctly 8.1 has 345hp, and the diesel has 360hp) but the diesel well out pull the 8.1 all over the place, a friends parrents had a 8.1l in a chev crew cab, pulling a 14000lb 5th wheel, they switched to a diesel, now they barely ever switch down more then a gear while going up steep inclines in the mountains, before, they were always jumping around gears. (keep in mind i believe that these trucks had the same transmission and rear ends)


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## JohnnyRoyale (Jun 18, 2006)

cubicinches;1023304 said:


> Soooo.... Uh, like, what's your vote?


He did say Torque.

Thanks for the new sig Leon. :laughing:


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## 2COR517 (Oct 23, 2008)

JohnnyRoyale;1023358 said:


> Thanks for the new sig Leon.


I guess that's OK........


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## jb1390 (Sep 23, 2008)

> ok then, i have a question, if what you say is true (and i am not calling you a liar) why is it that a 8.1 chev gas, has similar hp as the diesel in a 03, (if i remember correctly 8.1 has 345hp, and the diesel has 360hp) but the diesel well out pull the 8.1 all over the place, a friends parrents had a 8.1l in a chev crew cab, pulling a 14000lb 5th wheel, they switched to a diesel, now they barely ever switch down more then a gear while going up steep inclines in the mountains, before, they were always jumping around gears. (keep in mind i believe that these trucks had the same transmission and rear ends)


The reason is that the torque curve for the diesel is much more consistent. When the diesel drops in rpms, the torque will stay relatively the same, and for the 8.1 it will not. This means that the diesel does not need to shift-the slight drop in speed means less wind resistance, etc, so the load is slightly easier to pull. When the 8.1 drops in speed, the torque falls on its face. Assuming that gearing is the same and rear ends etc are the same, the torque at the flywheel determines how quickly the load will move. A diesel's consistent torque curve is the reason that it is a popular towing and plowing engine. The trick is that torque can be multiplied and divided at will using a gearbox.

To use another example, a steam boat engine close to me has 7000 foot pounds (or close to that) of torque. However, it can only turn at 100 rpms or so. By the time you gear that up to a diesel-imagine 500 foot pounds at 4000 rpm-the steam engine through a gearbox would have 175 foot pounds of torque at 4000 rpms. The diesel has way more power. Way less torque at the flywheel, but it will move a boat more quickly through the water.

One more example....imagine John Cena (or your favorite large person) on a bicycle. Then imagine lance armstrong. John Cena can pedal much harder than lance armstrong-no question. However, his ability to continue pedaling hard as rate increases is diminished. Lance can move his legs much much faster than John Cena. Which is why Lance armstrong will beat John Cena up a hill-even a short one so John Cena doesn't get tired. This will be true even if you add weight to Lance to make the two weight the same.


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## cubicinches (Oct 19, 2008)

JohnnyRoyale;1023358 said:


> He did say Torque.


When he edited at 12:49....


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## NICHOLS LANDSCA (Sep 15, 2007)

"Torque wins the race on Sunday Horsepower sells on Monday" Carroll Shelby Oh and that dyno sheet is BOGUS, HP and torque will always cross at 5252rpm.


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## wideout (Nov 18, 2009)

If thats the truth then y do semis have 3500ft lbs of tourqe and around 500hp? just a question


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## jb1390 (Sep 23, 2008)

Semi's cannot climb hills quick. And no semi truck driver likes driving with the engine racing. The truth is that a semi would climb a hill faster with a nascar engine than it would with a diesel. But it wouldn't last as long, would get terrible mileage, and wouldn't be cost effective to operate. Think about any vehicle built truly for speed-monster trucks are built around high horsepower, nascar, dragsters, tractor pulls etc. High horsepower will climb the hill faster than high torque. Period.

Also, with 3500 foot pounds of torque, you would be making 500 hp at 750 rpm, assuming a flat torque curve. So I think those numbers are probably a little off.

Here is a link that explains some of the math behind it. 
http://horsepowersports.com/torque.php


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## wideout (Nov 18, 2009)

Torque is what gets u up a hill plan and simple! Find two trucks set up the same way with as close as possible hp one gas one diesel then hook them up to the same trailer and pull them up a hill and see which one does it faster and easier the diesil will win every time


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## jb1390 (Sep 23, 2008)

Not because it has more torque-it is because it has a more flat torque curve. If it makes more sense-think about moving a boat through water. High horsepower will always make the boat move faster. 

Wideout you are getting confused by instantly jumping to the gas vs diesel without truly understanding the definitions of torque and horsepower and how they relate. If you had an IVT, then the highest horsepower engine will win up the hill every time. Since we don't have them yet in large trucks, a diesel engines flat torque curve will make it more capable of making it up the hill, since the torque does not drop off.


If torque will win every time-then let us race. You can have the 1990 Ford 7.3 IDI diesel. It has 360 ft lbs of torque (but only 185 horsepower, which you say will not matter). I get the vortec 350. It only has 330 foot pounds of torque, but it has 255 horsepower. Who do you think would win?


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## wideout (Nov 18, 2009)

Racing and pulling a heavy ass trailer are two different things and when it comes to gettind a load up a hill torque is your friend


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## jb1390 (Sep 23, 2008)

I will race you while each pulling a 10k trailer. You can have the idi with more torque. 

And when it comes to engines, torque and horsepower are very closely tied together. Simply looking at a torque number and saying that is the engine for me is foolish, since a torque number doesn't tell you how quickly the engine can apply that torque (which is why people would bet on the gasser to win in our race). See the above example of a steam engine with 7000 (yeah SEVEN THOUSAND) foot pounds of torque. If you put that engine in a truck, would it be the best choice?

So it isn't just torque. Horsepower is what moves you quickly. Modern diesels have comprable horsepower to the gassers, and a flatter torque curve. Which is why they are more powerful. Because they have more horsepower when the hill comes.


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## 2COR517 (Oct 23, 2008)

Here's something to think about, the calculation for Horsepower includes a time component. Torque is simply the measurement of twisting force.


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## jb1390 (Sep 23, 2008)

2cor517 which way did you vote? :waving:xysport


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## 2COR517 (Oct 23, 2008)

I haven't actually placed my vote yet, I wanted to see how it went. But I would be in the minority


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## cubicinches (Oct 19, 2008)

2COR517;1029393 said:


> But I would be in the minority


Smart man...

Torque vs. Horsepower is always a great debate to sit back and watch. That's why I grabbed some popcorn early on...


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## buckwheat_la (Oct 11, 2009)

so i did a search online to see what others have had to say on this subject, and i have come to this conclusion, it is kind of "glass half empty or half full debate" (or if you like "what came first the chicken or the egg") Torque matters because it well determine how much force is behind each rotation, but HP well get the speed going.


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## jb1390 (Sep 23, 2008)

You NEED torque to make horsepower. But torque without horsepower is useless when you are talking about moving a load. (you can have torque without moving anything-think stuck lug nuts) You cannot have horsepower without moving something. So when talking about moving a load up a hill, it's all horsepower.


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## 2COR517 (Oct 23, 2008)

cubicinches;1029400 said:


> Smart man...
> 
> Torque vs. Horsepower is always a great debate to sit back and watch.


Yeah, kinda slow around here with a light winter, just trying to get people involved. I was trying to generate a little activity on another thread, but was foiled


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## buckwheat_la (Oct 11, 2009)

jb1390;1029409 said:


> You NEED torque to make horsepower. But torque without horsepower is useless when you are talking about moving a load. (you can have torque without moving anything-think stuck lug nuts) You cannot have horsepower without moving something. So when talking about moving a load up a hill, it's all horsepower.


and so if you have 10 000 rpm and no/little torque to back it up, what happens? ever tried to put a heavy load/go up a hill on a engine that needs new rings, yep, that load/hill acts like a lead weight, and eventually STALLS!!!


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## blk90s13 (Sep 1, 2005)

ProTouchGrounds;1023091 said:


> i vote boost!


thats all you need


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## wideout (Nov 18, 2009)

So if I have 300hp and 150 ft lbs your sayin that would get you up a hill better than 150 hp and 300 lbs of torque?


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## jb1390 (Sep 23, 2008)

> So if I have 300hp and 150 ft lbs your sayin that would get you up a hill better than 150 hp and 300 lbs of torque?


Yes you will get up the hill faster.



> and so if you have 10 000 rpm and no/little torque to back it up, what happens? ever tried to put a heavy load/go up a hill on a engine that needs new rings, yep, that load/hill acts like a lead weight, and eventually STALLS!!!


What do you define as little torque? If you have zero torque, and 10,000 rpms, you will have zero horsepower.

So you will go slow because you need torque to make horsepower. It's basic physics-any decent high school physics student could explain it to you. An engine with bad rings will not be able to make horsepower.


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## 2COR517 (Oct 23, 2008)

ProTouchGrounds;1023091 said:


> i vote boost!





blk90s13;1029602 said:


> thats all you need


Does boost give you more HP or Torque?

Good way to avoid answering the question......


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## buckwheat_la (Oct 11, 2009)

jb1390;1029743 said:


> Yes you will get up the hill faster.
> 
> What do you define as little torque? If you have zero torque, and 10,000 rpms, you will have zero horsepower.
> 
> So you will go slow because you need torque to make horsepower. It's basic physics-any decent high school physics student could explain it to you. An engine with bad rings will not be able to make horsepower.


This is becoming a very dull conversation, there are two parts to the equation that make horsepower, torque and rpm divided by 5252 so my contention is that if the torque levels do not apply adequate force getting to the wheels to climb the grade (and the steeper the grade the more force is needed) then horespower means nothing, of course the only way you would get a higher HP is if you had high RPM, but it still means the same thing which is depending on your perspective an arguement can be made for either case, but in the end, both are needed.


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## Luther (Oct 31, 2007)

One can't exist without the other.

Using 2COR's example @ 50mph.......I say horsepower.


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## cubicinches (Oct 19, 2008)

buckwheat_la;1029762 said:


> This is becoming a very dull conversation, there are two parts to the equation that make horsepower, torque and rpm divided by 5252 so my contention is that if the torque levels do not apply adequate force getting to the wheels to climb the grade (and the steeper the grade the more force is needed) then horespower means nothing, of course the only way you would get a higher HP is if you had high RPM, but it still means the same thing which is depending on your perspective an arguement can be made for either case, but in the end, both are needed.


Despite anyone's perspective, the laws of physics dictate that there is only one correct answer. It's true that arguments can be made for either case, but they're still only arguments. :waving:


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## cubicinches (Oct 19, 2008)

2COR517;1029751 said:


> Does boost give you more HP or Torque?


It depends on how big the hill is and how heavy your vehicle is...

Oh, and what condition your piston rings are in.


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## Sydenstricker Landscaping (Dec 17, 2006)

I voted torque, what do I win?? LOL I always try to keep the torque numbers higher than the hp numbers with my truck. I like to be able to rip tree stumps out, lol


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## 2COR517 (Oct 23, 2008)

Sydenstricker Landscaping;1030649 said:


> I voted torque, what do I win?? LOL I always try to keep the torque numbers higher than the hp numbers with my truck. I like to be able to rip tree stumps out, lol


What if you are measuring torque in Newton-Meters and power in Kilowatts?


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## 2COR517 (Oct 23, 2008)

cubicinches;1030627 said:


> It depends on how big the hill is and how heavy your vehicle is...
> 
> Oh, and what condition your piston rings are in.


What are piston rings? And how do I check them? Does AutoZone do that for free?


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## cubicinches (Oct 19, 2008)

2COR517;1030665 said:


> What are piston rings? And how do I check them? Does AutoZone do that for free?


I think Auto Zone does check them... cuz they sell that stuff in a bottle that fixes 'em up better than new. So, they _must_ check them there... I would think.


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## Sydenstricker Landscaping (Dec 17, 2006)

2COR517;1030663 said:


> What if you are measuring torque in Newton-Meters and power in Kilowatts?


Depends on how my canuter valve and flux capacitor was working. Last I checked it was 1.25 gigawatts, lmao:laughing:


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## T-MAN (Jan 9, 2001)

2COR517;1030665 said:


> What are piston rings? And how do I check them? Does AutoZone do that for free?


compression test dry, then with a couple drops of oil. 

I guess the one thing not thrown out yet is how do you make HP ?
It takes fuel to make HP. If your in the game to make money, then less fuel usually means a higher profit. 
So your high rpm vortec might beat the naturally aspirated 7.3 up the hill, but in the end Exxon will actually be the winner


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## jb1390 (Sep 23, 2008)

> I guess the one thing not thrown out yet is how do you make HP ?
> It takes fuel to make HP. If your in the game to make money, then less fuel usually means a higher profit.
> So your high rpm vortec might beat the naturally aspirated 7.3 up the hill, but in the end Exxon will actually be the winner
> __________________


Totally agreed-which is why semis are diesel. Not because they will win the race up the hill.


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## sven_502 (Nov 1, 2008)

I read somewhere that horsepower is how fast you hit the wall, and torque is how far you're going to push it when you hit it. Seemed accurate to me, but somebody tell me otherwise.


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## harleyfxdl (Feb 4, 2010)

The answer lies here:
http://www.vettenet.org/torquehp.html


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## cubicinches (Oct 19, 2008)

harleyfxdl;1031215 said:


> The answer lies here:
> http://www.vettenet.org/torquehp.html


I've been waiting for that to come up. That piece by Bruce Augenstein has been kicking around the internet for a long time now... You do realize that the second part of that, was written by someone else (Thomas Barber, whoever he is), in response to Augenstein's explanation.

The most sensible part of that whole thing, explanation and response, is this:

Foremost, the explanation should articulate the essential fact that acceleration at any time is proportional to power, along with the essential fact that the acceleration associated with any specific amount of engine torque, depends on the engine speed.

Regardless of whether the explanation articulates those essential facts, it must not espouse any fallacious notions that are contrary to those facts.

If the explanation endeavors to explain any fundamental physical concepts such as torque, work, and power, those explanations should be fundamentally correct. 

So... If you feel, as you stated, that the answer lies within all of what is written there...

What is the answer? And, how did you vote?


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## THEGOLDPRO (Jun 18, 2006)

TQ gets you going, HP keeps you going.


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## harleyfxdl (Feb 4, 2010)

I voted torque. When pulling, the feeling of being pushed into your seat, that is torque. If you look at most 18-wheelers, the engines, most I-6, have 450 hp but 1200 lbs torque. If I took a big block chevy with 450 hp and 550 torque and put it in the truck, it would not pull the same load up a 10% grade. Torque is what does the work in an engine. My .02, no change required.


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## jb1390 (Sep 23, 2008)

The feeling of being pushed into your seat is torque AT THE WHEELS. Nothing-zero-to do with torque at the engine. A big block chevy with 550 hp will outpull any diesel in the world with 450 hp if they both have an ivt transmission.


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