Horsepower vs Torque – A Simple Explanation
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Horsepower vs Torque – A Simple Explanation

August 12, 2019


Hello everyone and welcome. In this video we’re going to be talking about the difference between torque and horsepower. And we’re not going to be using any strange analogies and very minimal math; just talking about theory and keeping it easy to understand. So we’ll start things off with torque.
Torque is simply a force applied at a distance. You can think of it as a twisting force. So if you’re trying to tighten something down using a wrench, You apply a force, you press down at a distance, the length of that wrench, and that supplies a torque at whatever you’re tightening. Same idea with a socket wrench. So if you’re tightening down a bolt you apply a force at a distance, And that supplies a torque to that bolt to fasten down that bolt. Now the same thing is happening with your engine. So combustion within your cylinder is what’s supplying the force pressing this piston down, and then that piston is pressing down on a crankshaft. So as you can see, you’ve got your force pressing down, You’ve got your distance where it’s pressing on the crankshaft, the axis of rotation is the center here the piston is pressing offset from that center so at a specific distance and Combined that gives you your engine torque, force pressing down at a specific distance that gives you a twisting force That’s the torque that your engine is making now torque can be manipulated very easily By using gears or by using leverage for example So this will supply you know with the maximum amount of force I can supply to it a certain amount of torque But then if I were to use something much longer Now I have more leverage I can press at a greater distance and since torque is force multiplied by distance The torque here is going to be significantly greater Okay, so what is power and how do these two relate? Well, power is the rate at which work is done So what does that mean? Well if I move this car from here to here. I’ve done a certain amount of work I’ve moved this from here to here, now if I do it very slowly it doesn’t require much power. if I do it very quickly it requires more power Now ultimately I’m accomplishing the same thing I’m moving the car from here to here, but I’m doing it faster The rate of work is greater therefore It takes more power so more power going quickly than going slowly So power ultimately is what gives you speed, what gives you acceleration now the two are connected so in in our context Here looking at our engine. We have torque as a force pressing down acting at a distance Well how fast that’s happening is our power so that’s our rpm. So horsepower is torque multiplied by rpm So how often this interaction is occurring… And so how fast is this spinning while we’re still getting that consistent force acting on the piston so the faster it spins Supplying that same amount of force at that same distance the more power we’re going to make Okay, so how about an example to help explain things further? Let’s say we have two different vehicles that are exactly the same. Now, I know these look different, but we’re just going to pretend They’re exactly the same nothing about them is different except this one has 200 horsepower and a hundred pound feet of torque Those are the peak numbers. This one has 200 pound feet of torque and a hundred horsepower so half the power Twice the torque this one has twice the power half the torque Which one is going to accelerate faster assuming both of them have the same mass? And everything else about them is equal Well the one with more power is always going to be quicker because that is the rate at which work is done That’s how quickly it can accomplish work move something from one place to another it can move it faster Now this one has more torque, great But as we know torque can be manipulated through gearing so gears act just like leverage So while this doesn’t have as much torque as this If I’m applying torque to something I – my power doesn’t change, how strong I am doesn’t change But I can use leverage just like cars can use gears to make more torque so this car with twice the power But half the torque can use gears to accelerate faster, so it can use a longer You know leverage arm a greater a more aggressive gear ratio So that it can put that power down and ultimately because it makes more power it can do more work more quickly It will be the faster car. Okay so now let’s talk about horsepower and torque curves because when a manufacturer gives you a horsepower and a torque figure They’re just giving you the peak figure for each of those They’re not giving you, you know the amount of torque that that produces across all of the engine rpm range And so if you look at a torque curve, it’ll have some peak along that curve with respect to rpm so that’s the engine rpm in which the force pressing down on the piston is at its greatest so that’s peak torque and what that means if you stay within a set gear, if you’re in one gear let’s say you’re in third gear, you will feel the – the force pressing you against your seat will be the greatest at peak torque now That’s assuming you’re staying at a constant gear ratio You’re staying within one gear So now if you look at the horse power curve overlaid over that torque curve At some point, peak horsepower will occur And that’s when the engine is doing the most amount of work it can do and so at this point You may think okay if I want to accelerate fastest I need to be at peak torque, so you want to be at that peak spot Well, that’s only true for a set gear and that’s only within that gear if you can manipulate the gear ratio Let’s say peak torque is right here But peak power is over here, later in the RPM range you can sacrifice torque But get a more aggressive gear ratio, and ultimately accelerate more quickly by accelerating at peak power So why is that well that’s because you’re multiplying your torque by the gear ratio So you have peak torque multiplied by a lower gear ratio versus a lower torque But multiplied by a significantly higher gear ratio at peak horsepower That will give you your peak acceleration So for example CVT transmissions Which can adjust the gear ratio constantly If they adjust that gear ratio to maintain the engine at peak horsepower They will accelerate the fastest rather than if you were to manually shift gears, or have an automatic transmission Which shifts between gears and you’ll feel that peak sensation that peak force against the seat at peak torque as you cross over it, but the actual true amount of peak acceleration That’s possible with that engine would be if you manipulated gearing if you Manipulated leverage to allow you to be at the highest horsepower Level with the most aggressive gear ratio possible so a quick review, torque is simply a force acting at a distance Horsepower is how quickly you can accomplish work, now both of them require each other They’re a function of each other horsepower is torque multiplied by rpm, so you’ve got a specific torque and then you spin the engine at a certain speed, that will give you power And so ultimately they are you know they require one another you can’t have horsepower without torque But the most important figure if you’re looking at “how fast will a car be able to accelerate?” “What will its top speed be?” that comes down to power because that’s telling you how quickly? Can you accomplish a certain amount of work So hopefully this has cleared things up; the differences between torque and horsepower If you have any questions or comments, feel free to leave them below. Thanks for watching

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  1. you did not explain what is the advantage of high torque.
    you only told high bhp = faster.
    high torque = ??

  2. It is simple..

    Torque comes from force – that is what pushes things. From the piston to the wheels.

    HP is at what speed you use the force, equally how much you move in a given timeframe. – That's called power.

    Well to move a heavy thing you can not use a high reving engine with low torque (force). The engine wouldn't be able to come up to speed so you can get the HP..
    Ex.Use a motorcycle engine to move a heavy truck.

    You can do it the other way by using gears so, a truck engine can get a motorcycle (it would be a huge and heavy one) up to speed despite not having so much HP.

    Conclusion: You need enough Force (Torque) for your weight!

  3. If I remember this definition correctly one horsepower is the ability to carry a half a ton of weight up a 15-degree incline for a distance of a quarter mile torque is a constant force of twisting on the axle!

  4. In a realistic fashion (considering I live in Britain, where there are barely any wide open roads) I think that torque is better to have, it just feels better in my opinion and you'd use it more.

  5. So the peak force throwing you back in your seat happens at peak torque but peak acceleration happens at peak horsepower? This is precisely what words came out of your mouth during the video, sorry, I just don't see how the force throwing me back in my seat and vehicle acceleration could be 2 different things.

  6. Perhaps if we assume a flat torque curve, we could then say, for a given combustion event, the force of explosion is constant at all rpms, (definition of a flat torque curve right?) and therefore, hp is zero at rpm =0 and would increase linearly as rpm was increased. Or at rpm 1000 there were x force events per minute and at 2000 rpm there were 2x force events per minute. Obviously then the higher the revs, the more force events, each force event on a flat torque curve is constant, so more work per unit time or a faster driving experience. Introducing gearing into this video I think just over complicates it. It shows you just how hard it is to understand the topic, not event this very smart guy is able to understand it.

  7. The way I look at it is horsepower is of the amount of power an engine can produce, torque is the engines ability to reach its horsepower quickly.

  8. Torque is how hard you punch a punching bag, HP is how fast you hit it. The ideal goal being to hit it as hard and fast as you can, the same applies to vehicles, well, performance vehicles anyway.

  9. 3 minutes, 59 seconds in… and this explanation is still more vastly overcomplicated than was promised in the beginning.

    It's very simple. Torque, is rotational force applied. Horsepower, is the application of said force to do work. In the case of engines… torque rating is the maximum rotational pressure immediately available at the crank… while horsepower is representative of the maximum amount of pressure available through optimized gearing.

  10. Only people who have no clue about the very basics of physics concerning energy, power, motion, force and torque will be confused about this topic. Seems something is horribly rotten in the American educational system.

  11. Am I the only one thinking how antequated the term "horsepower" sounds? There's torque which sounds sciency, then friggen "horse" power? wtf. Let's all get metric finally.

  12. I have a question. What are the advantages and disadvantages of these?

    1. A car with high hp and low torque(200hp/100lb-ft)?
    2. A car with low hp and high torque(100hp/200lb-ft)?

    Thank you in advance. 🙂

  13. Personally I want them to switch to either "average horsepower to 60 mph" or "average horsepower from idle to redline through all gears up to 90 mph". Or even "average horsepower from 10 mph to 60 mph". This way of calculating horsepower would be way more useful than peak horsepower that because of gearing may only be used 10% of the time.

  14. great explanation, however noted that the comparison (HP vs Torque) between those two cars were of the same type and weight. When the comparing vehicles were not the same, eg a school bus and a compact passenger car, even though the school bus has 200HP it won't accelerate faster than the passenger car, here weight is a big factor.

  15. Harley and gxsr drag race. Harley always takes first half and gxsr always catches up by end of 1/4mile as horsepower overrides torq

  16. "the most force you feel is at peak torque" wrong. Torque at the engine =/= torque at the wheels. I think that part is going to confuse people.

    What you feel is the result of change over time. That'll occur at peak power even if the engine is 1:1

  17. HP is torque multiplied by RPM. Torque is mainly determined by engine displacement. HP is what you want, if you are low on torque, gears make up for it. HP is power.

  18. hi, i have a Q… suppose i need to buy a motorcycle which one i should buy and why ? 1) 15 hp / 11 torque and 2) 14 hp / 14 torque … which 1 is better and why ???

  19. Great effort. But slow down your speech rate while explaining since sometimes it becomes difficult to follow with terms not defined. Thanks.

  20. To put it simple , I think torque is when u need a force to move a heavy object and power is when u need to move slightly lighter object little faster . 🐘 Torque…. 🏇 power !!

  21. Actually, he is incorrect.

    Force • Distance = Work, not torque. Horsepower is a unit of measuring work. In this case, the equation above, is calculated as follows:
    (Area of piston head) • Stroke length (usually the length of the bore, from Top Dead Center to Bottom Dead Center). Some people say that stroke is more accurately the distance the connecting rod travels as the crankshaft rotates. This is why, if you increase your connecting rod length, you get more horsepower, but if you increase piston area, you get more torque.

    For example, Ford used the 2.3L Lima four-cylinder engine. It was rated at 100 HP. Later, Ford developed the 2.5L engine. Similar to the 2.3, the 2.5 had higher horsepower because of an increase of the connecting rods by 7 millimeters. That may not seem like much, but with an increase of fuel pressure, the horsepower rating jumped from 100 HP in 1992 to over 140 HP by 2001.

    Speed AND acceleration are calculated by: Distance • Time.

    Torque is actually angular momentum with applied pressure. The pressure that is applied, rotationally, is the measurement of torque that is usually referred to.

    On a car, you have four distinct areas of torque: Torque at the engine, torque at the transmission, torque at your differential (for AWD and RWD cars), and torque at the wheels. In each case, you have to overcome the inertia of the parts involved in order to rotate, which is referred to as "minimum torque." For example, you could lock your front brakes and attempt to do a burn-out. But if your torque at your rear wheels is not enough to overcome the pressure required by the tires and weight of the wheels, your wheels won't spin, because friction between the surface of the road and your tires will prevent the tires from spinning.

  22. Tractors have more torque than horsepower this is why they are slow but can pull big ploughs. Cars have more horsepower than torque this is why they can go faster but would struggle with things like heavy towing etc.

  23. I added this to “watch later” to view when I’m not drunk. This got deep quickly despite what the intro promised or maybe I’m just hammered.

  24. I'm just interested in how fast a car will accelerate. Which of these do I consider most, hp or torque, when buying a vehicle? Not clear to me from the video.

  25. Hi, i remember you have a video that you were in thr desert? You were doing this vlog with another guy, i wanna watch that again but i forgot what it was, maybe you can help me with the link? Thanns

  26. Sir one question how max power and torque figures are achieved at standard rpms like 6000 or 6500 or 5000 why not in odd figures 5576rpm or 6243rpm how is this?

  27. Wow. Some days back I was searching to understand it better. Glad to see the best version of the explanation. Thank you very much.

  28. In the past I drove rallies with a 1981 Opel Ascona B 2.0E. At 1st I used
    the original engine bottom block. To keep the car in the 2.0 class we
    used the original crankshaft and used BMW piston rods, which are 7 mm
    longer and Opel Omega pistons.(The pistonpen is 7mm(0.276 of an inch)
    higher in the piston. This also gives more torque in the lower rpm's
    without changing the stroke. So a straighter angle from the piston rod
    to the crankshaft gives more torque….

  29. A simple explanation? Are you serious?4 minutes of repetitive, incomprehensible drivel. If any sense was made I am sorry but I did not have the stomach to continue to watch.If you have something to say I suggest you employ the old adage "before engaging mouth, ensure the brain is in gear. Put simply write it down and make an effort to make it coherent.

  30. You told us the value of a lot of HP but not the value of having a lot of torque.
    So if I have a lot of HP then I can accelerate faster.
    But if I have more torque…. Then what?
    Harley's are know for their torque not their HP so what is the value of
    a motorcycle being know for its torque? How does that translate into
    riding a Harley for example. Please folks make constructive comments
    so we can all learn! thank you.

  31. In simple terms, you are correct. But just like elementary math that changes in middle school and then high school, you are only correct until more variables come into play. Yes, a car with no outside forces acting on it will be faster with more horsepower than a car with more torque. But if you look at the forces in total it becomes a more complicated story as you have to account for outside forces as well as the job that the work is designed to accomplish. When it comes to engines there is Naturally Aspirated and Forced Induction(and nitrous, but that's a separate story). A naturally aspirated engine will benefit from a modest mix of both torque(bore size x stroke) and horsepower(RPM limit). While a forced induction motor can push the limits of what is possible, allowing you to have more bore size and stroke which leads to more torque and on the other end more horsepower due to a loss of vacuum and instead a positive pressure environment which means the engine can turn at a faster rpm. Due to limits in internal combustion, if the force of the combustion remains constant, the only variable to which can be increased is the RPM limit on vehicles with lower displacement allowing them to have high horsepower but low torque. Meaning, in layman's terms, you must counteract the outside forces with torque before applying your horsepower advantage. I just wrote all this to say… "There is no replacement for Displacement."

  32. next time some white trash hick says "horsepower sells cars, torque wins races", link them this video.

  33. Basically if u have two cars. Both of them have same power but one of them has more torque. The car which have more torque should give you a feeling that your car is speeding much better. But both of them have same time lets say 0 to 60mph or 0 to 100km/h.

  34. If torque multiplied by rpm's gives your horsepower how do we have engines with peak torque higher than peak horsepower? For example a diesel engine with 700lb-ft of torque but only 350 peak hp? What's the reason and the math?

  35. I still cant fathom a piston moving up and down 100 times a second while an engine is turning 3000 rpms….if you only count the UPs its still 50 times per second. A piston the size of my fist is moving up or down 50 times a second while im driving my old 350 powered gmc. WTF

  36. Torque is twisting force and what makes a car accelerate fast, while horsepower is the total capacity for work, which affects top speed. That is the fundamental reason why an electric vehicle will go zero to sixty so quickly. Electric motors have high torquqe versus a relatively low horsepower. Again, torque delivers rate of change, aka – acceleration, and horsepower delivers top speed, aka maximum work done.

  37. Horse power – how fast will you hit the wall.. Torque – how far will you drag that wall with you 🙂

  38. base on my understanding, torque is far more important than power because torque is the key to make a car to start up fast,that is especially important in low speed situations such as driving in the city.

  39. One question: If horsepower is torque x velocity, the why do some engines have more torque than HP? Not being a smart-aleck, I really just don't understand that.

  40. It might be easier to think of capacity of an engine. For any given capacity the volume of the cylinder is a function of stroke length and bore diameter. I high reving engine willl have a shorter stroke and wider bore. A low reving engine has a narrower bore and longer stroke for the same capacity. The short stroke alllows an engine to rev faster – tending to produce more power. This comes at a cost of lower torque so less pulling power. The engine can rev but soon as it is loaded down for example in a car that starts going up a hill the short stroke of the engine (and therefore smaller throw of the crank – shorter lever arm) means the torque is not there to pull harder and turn the wheels – without a down change in gears the car stalls.. The long stroke engine mean it takes longer to do each revolution of the crankshaft but the longer throw of the crank means that at any point in the rotation of the crank the connectimg rod
    is further out from the centreline of the crank so the lever arm is longer and torque higher.. You get up that steep hill
    but when back on level ground you are stuck with an engine that rotates inherently slower i.e. produces lower power.

  41. So if torque can be manipulated by gears then why is there a curve for torque rather than a broken line for each individual gear?

  42. In your recent G-Wagen vid you said it can climb a 100% grade. If I'm halfway up a hill (100% grade) at a dead stop in my manual trans car, to get moving (upward) do I want torque or power. My instinct and experience say torque. What does EE say? Thanks.
    (Or is it that I need HP at the engine and gear multiplication for max torque at the wheels?)

  43. If horsepower is quicker on the start…Then why will a torquey V-twin motorcycle with only a 80 hp engine and more weight, beat a lighter high powered in-line 4 sportbike off the line every time?

  44. What puzzles me is Neuton metre to Foot lbs direct conversions….I mean if your lever is a meter long for a nm with 1kg of force on it for 1 nm,then surely a nm would be around 660 percent that of a foot lb and not only 36 percent greater….does anyone know what I mean?`
    well then again if you ignore levers and just consider the movement of the weights in each case through their respective distances….and then divide the weight by the distance,to get their comparable force……..then yeah seeing as the metre is nearly 3 times longer than the foot into a weight only 2.2 times the ft lb….,I guess I kinda get it now.It's not very intuitive.

  45. Finally someone that focus on people understanding this and no trying to show off by confusing something as simple as this. Good job!

  46. This was confusing at the end. So in what rev range should i try to keep it, when racing. Between peak torque & peak power? Or as close as possible to peak power, to rev limiter basically?

  47. A 60 ton Leopard 2 tank only has 50% more horsepower than an 800 kg F1 car (1500 vs 1000), but almost seven times the torque (4700 vs 700 nm).

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