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Difference between torque and HP???

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Scotty, in a recent video you said that an electric truck had more torque and thats what you needed to pull stuff. So, what's the difference between torque and horse power? I know it's a dumb question, but I'm sure other people are wondering.

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5

https://m.youtube.com/watch?v=u-MH4sf5xkY

5

consider this ...

A very high performance race car can make 1,000 hp. But so can a tank.

One can reaches very high speeds and the other doesn't. One can pull a loaded bus up a hill, the other can't.

Horsepower is a just a measure of total energy, and doesn't actually provide much information about how it's delivered. Torque is the amount of force something has (think of an arm wrestle), but again it doesn't tell you enough.

 

To really characterize an engine or vehicle, you need to look at a performance curve. Torque versus RPM. You will see tanks, tractors, bulldozers etc develop their peak torque/power in the low RPM range. Race cars need to make power at very high speed/RPM.

This is actually a really good post. Probably the best way to put it actually.

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So let’s say you’re tightening two different nuts:

  1. let’s say one is really hard to tighten (25NM) and you do it slowly (1 RPM)
  2. and the other is very easy to tighten (1NM) but you do it fast (25RPM)

in both these cases, you’ve input the same amount of power (horsepower) but the difference was torque.

 

Torque is basically how hard can the engine turn the wheels. And you need this in an SUV or a Truck to get rolling easier (here turning the wheels can be more difficult)

 

( The physics equation is P = t * ω )

a lot of modern engines, my favorite example is the BoosterJet line Suzuki that does deliver both a lot of torque and a lot horsepower from a very small displacement.

Here is an engine curve from a Volvo T5 engine.
The red graph is how hard each turn of the wheels is,
The blue graph is how much power is made overall.
This graph explains how the engine behaves for each RPM setting.

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and the gearbox is there to keep the engine rpm in the correct range to make the optimal torque / horsepower at each setting depending on driving conditions.
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The physics behind internal combustion engines are quite complicated

That is fantastic! Thank you!

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Scotty's explanation:

Hey that's great! I had no idea this video existed. Thanks !

You're welcome man.

2

It's not a dumb question at all.  Here are some analogies:

Difference between volts and amps

Difference between PSI and CFM.

If you get these analogies, you get the difference between HP ans Torque.

like Volts and Watts would be more accurate

See, I can understand volts and watts. Thats more my speed because I work on motherboards and electronics for a living. Thanks!

there you go, and since Watts are a unit of power you can also use them to express a car's output.

1 horsepower = 746 Watts.

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Someone correct me if I am wrong. 

Think if it like a punch. 

A fast punch is like torque. 

A strong punch is like horsepower. 

other way around

GTK. Thank you!

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If I remember correctly, I think horsepower was how much power the engine had, and torque was how long you felt the power. Kinda like how diesel trucks have like 1000 pound feet of torque, so you feel that 400 HP for a longer period of time at higher speed, it's kinda hard to explain. Someone feel free to correct me if I'm wrong.

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"Horsepower sells cars. Torque wins races."

- Mr. Carroll Shelby

well you can't win a race with no HP that's for sure Smile

and the best analogy for this is a sprinter vs. power lifter
power lifter will never be able to outrun the sprinter cause he lacks HP but you can bet once he lays his hands on him he can rip him in half with no problems Grin

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