Destroying a myth: no, torque does not matter, power does. Because physics!

[fgaliegue]

When a vehicle of mass m going at velocity v wants to keep moving, it has to counter three forces:

* rolling resistance: Fr = Crr * m * g;
* aerodynamic drag: Fd = 1/2 * A * Cd * rho * v^2;
* gravity: Fg = m * g * sin(gradient)

That's oversimplified, of course, but the fact is this: IN ORDER TO KEEP MOVING, the truck has to provide a force F = Fr + Fd + Fg... At a velocity v.

And, physics 101: F * v is POWER. The engine has therefore the duty to provide enough power to just keep countering those three forces at the current velocity.

If you do not provide enough power, you... Slow down. The rest of the power just helps you accelerate. Therefore increasing the need for power again, because aerodynamics.

It just happens that power is also a torque multiplied by a frequency... And rpm IS a frequency, ultimately: one round is 2 * pi radians. This is why the torque/power curve of engines is so important.

So, you just have to be in the correct gear at a given time so that the engine provides enough... Power... To keep the truck moving and then some, ie accelerating.

Of course, that's oversimplified. More details on demand...

[Sandhill]

In the day I had a Kawasaki H1 Mach III which made 60 hp out of 500cc, 120 hp/liter is pretty good for carburated but necessitated a narrow power band, it only happened at ZINGGING rpm., I had a couple for friends riding Bonnevilles at 50 hp from 650cc. In day to day riding I could NEVER keep up with them, I had to start from stopped at like 4000 rpm to keep the H1 from bogging down entirely while the Triumphs could just roll on power from 900 rpm.
They had similar torque at red line, but the Kaw had none until half way to red line, the Trumpets near max torque almost from idle. After a quarter mile at full throttle the Kaw would be going faster, but it was a miserable thing to drive, having to drop a gear at the slightest hint of a hill etc. To someone living with an engine on the job, a broad torque band beats a narrow HP band EVERY time

[MirkoC407]

But speaking of motorbikes - so OP should confirm that a distribution truck could be powered by the engine taken from a Yamaha YZF-R1. I mean that thing has 200 hp. An MAN TGL or its US sibling International MV can be bought with around 200 hp as well. Okay, the MAN D0834 in its 180 hp and the Cummins B6.7 in its 200 hp variant both deliver quite on the point 700 Nm. According to them this is irrelevant and the Yamaha RN engine with 112 Nm but the same horsepower should be equally suitable to move 12 tons gross weight. Waiting for their answer with excitement

[_KC76_]

Originally posted by MirkoC407:

But speaking of motorbikes - so OP should confirm that a distribution truck could be powered by the engine taken from a Yamaha YZF-R1. I mean that thing has 200 hp. An MAN TGL or its US sibling International MV can be bought with around 200 hp as well. Okay, the MAN D0834 in its 180 hp and the Cummins B6.7 in its 200 hp variant both deliver quite on the point 700 Nm. According to them this is irrelevant and the Yamaha RN engine with 112 Nm but the same horsepower should be equally suitable to move 12 tons gross weight. Waiting for their answer with excitement

Impersonating OP: WeLl AcTuAlLy, if the motobicycle puffer could poot poot at 4 million-bazillion Revums per Scootch, it would ObViOuSlY be the better scookum choocher.

[Wolfgang]

Originally posted by fgaliegue:

I love to see how you all get it all wrong...

Come on, guys, just learn physics.

Again: WHO CARES that there is an engine in a truck and that this engine is what provides work over time (ie, POWER)?

A truck is just a mass that needs to be moved a certain distance (that's energy), ideally as fast as possible (again, POWER: energy divided by time).

Whether the means to achieve that is a jet engine, a combustion engine or an electric powertrain, the fact remains that the goal is to provide that amount of work in as little time as possible.

Oh, and energy divided by time? That's power...

Get a grip. Learn physics.

And don't you worry, I know what torque is... More than you, as it were.

I'd like to quote Bing AI again:

Originally posted by Bing AI:

Relation to Horsepower: Torque represents the work an engine can do, and horsepower is its ability to do that work quickly. If you want to move heavy loads, you need a lot of torque. If you want to move heavy loads fast, get more horsepower.

You can not move a load if you have no or too little torque. If torque didn't matter we wouldn't need any truck engines at all but could use the same weedwhacker engine for all vehicles.
Yet, this isn't done. And you should ask yourself why.

[PajamaBanana]

:popcorn:

[mojo_musica]

Originally posted by PajamaBanana:

:popcorn:

Lots and lots of popcorn...
This is one hell of a ride, OP is totally clue-resistant and absurdly entertaining!

[[ BBS ] Bootleg]

Who would've thought all the old Greeks were liars, the Romans were liars, the Byzantines were liars, the ancient Turks were liars, the ancient Chinese were liars. And the list of liars goes on....

Which begs the question: did any of them really have no fundamental understanding of physics? Or maybe it's OP that doesn't understand the first thing about basic physics?

[MirkoC407]

Originally posted by BBS Bootleg:

Who would've thought all the old Greeks were liars, the Romans were liars, the Byzantines were liars, the ancient Turks were liars, the ancient Chinese were liars. And the list of liars goes on....

Which begs the question: did any of them really have no fundamental understanding of physics? Or maybe it's OP that doesn't understand the first thing about basic physics?

I'm waiting any moment for OP blaming us of being part of the "torque conspiracy"

[Wolfgang]

Originally posted by MirkoC407:

Originally posted by BBS Bootleg:

Who would've thought all the old Greeks were liars, the Romans were liars, the Byzantines were liars, the ancient Turks were liars, the ancient Chinese were liars. And the list of liars goes on....

Which begs the question: did any of them really have no fundamental understanding of physics? Or maybe it's OP that doesn't understand the first thing about basic physics?

I'm waiting any moment for OP blaming us of being part of the "torque conspiracy"

A conspiracy, eh?

Oh, wait. Seems like I am part of it.

[ZombieHunter]

Originally posted by MirkoC407:

Well, the even "better" (2 double expansion, i.e. technically 4 cylinders) German class 24, also a 2-6-0, has 900 hp (calculated power, you cannot measure it for a steam engine as simply as for a combustion engine). So for what it can move that is actually not much.

I was mostly looking for something being able to pull a lot of weight at low "rpm", which a steam engine perfectly does, because OP thinks their 60 rpm engine was a failure, while the 60 billion rpm bublebee on stereoids would be a monster mover.
The steam loco comparison was mostly there to show that "rpm is nothing without torque" by counterproof that "sufficient torque works well without rpm".

Ships are a good example. Very low RPM but extremely high torque. Some of those might run max 500 RPM but b/c of their extremely high torque end up producing well over 25,000 to 100,000+ hp. They aren't exactly fast, but they could pull your house off its foundation and into the water with it AND likely take it along the entire journey and never flinch. Without torque, they would never move.

To an extent piston engine aircraft are also a good example. That is b/c the max RPM on them is around 2600 to 2700 RPM. The reason for this is b/c if they go any faster the tips of the blades will break the sound barrier and that is not good at all. So to keep them under the speed of sound they limit the RPM. B/c of this the only way to get more horsepower, short of turbos, is to increase the torque. You can add cylinders to an extent but weight becomes a problem pretty quick. Weight is a huge factor when it comes to aviation. Most piston engine aircraft are air cooled, not liquid cooled, to save on weight. I say most b/c some inlines are liquid cooled b/c it is hard to cool these. Again, there are so many designs but the RPM limits are close to the same on all of them due to prop tips breaking the sound barrier at higher RPMs.

The best thing about torque is if an engine has more torque it can be ran at lower RPM and still have high horsepower. An engine that has to be run at high RPM due to low torque is probably not going to last as long as an engine that can produce the same horsepower with 50% or 75% of the RPM of another.

[HuskyDynamics]

"Am I possibly incorrect about the relationship between torque and horsepower and how they work? No, it must be the entire internal combustion engine industry that is wrong."

[physbo]

Originally posted by fgaliegue:

I love to see how you all get it all wrong...

Come on, guys, just learn physics.

Again: WHO CARES that there is an engine in a truck and that this engine is what provides work over time (ie, POWER)?

A truck is just a mass that needs to be moved a certain distance (that's energy), ideally as fast as possible (again, POWER: energy divided by time).

Whether the means to achieve that is a jet engine, a combustion engine or an electric powertrain, the fact remains that the goal is to provide that amount of work in as little time as possible.

Oh, and energy divided by time? That's power...

Get a grip. Learn physics.

And don't you worry, I know what torque is... More than you, as it were.

Are you talking about this? kW= 2π×Torque (Nm)×RPM divided by 60,000

Remember that torque is rotational force that is required to get something moving. Semis and large vehicles need more torque to get moving because of weight and drag. HP and Power is a different measurement but still works hand in hand with torque.


​

[[ BBS ] Bootleg]

Heard another funny take on this topic on a different platform a while ago. (this is going viral by looks of it). This one guy claimed "rpm is what matters first and foremost, only then it's down to horsepower, and third place goes to torque"

So in his perception, apparently a mini drone from a toy store can move more weight faster than an ocean cruiser simply due to it's high rpm. Oversimplified, of course.

Isn't this a fantastic world we live in these days? Seems the education systems around the world are really paying off.

[Wolfgang]

Originally posted by BBS Bootleg:

Heard another funny take on this topic on a different platform a while ago. (this is going viral by looks of it). This one guy claimed "rpm is what matters first and foremost, only then it's down to horsepower, and third place goes to torque"

So in his perception, apparently a mini drone from a toy store can move more weight faster than an ocean cruiser simply due to it's high rpm. Oversimplified, of course.

Isn't this a fantastic world we live in these days? Seems the education systems around the world are really paying off.

And that in a day and age where knowledge is easier accessible than ever.

[MirkoC407]

Originally posted by Wolfgang:

And that in a day and age where knowledge is easier accessible than ever. :steamdeadpan:

That statement unfortunately also applies to half-knowledge. And then it is only a short step to proof that two half-knowledges added does not equal full knowledge.