# Horsepower vs Torque – Explained

so this video is made to explain the difference between horsepower and torque now I’m going to start off by going a little into the math and the units of horsepower and torque and then I’m going to give you an analogy so that you can better understand what a car with a high torque means or a car with high horsepower means so horsepower is in units of foot-pounds per unit time for example if you were unit of time those minutes one horsepower would be equivalent to 33,000 foot-pounds per minute torque however is in units of pound-feet so horsepower is basically torque per unit time now there’s a direct relationship between horsepower and torque involving rpms there are revolutions per minute of your engine the engine speed so horsepower is equal to torque multiplied by our RPM multiplied for 2 pi one full revolution divided by 33 thousand foot-pounds per minute so this actually creates an interesting phenomena and so you’ve got horsepower is equal to torque times rpm over five thousand two hundred fifty two so this number right here is pretty important on a diameter when you look at the horsepower and torque here’s just a little fake one that I made up your horsepower will cross with torque at that RPM 52 52 and that’s because once your RPM exceeds 52 52 you’re going to be multiplying the torque by a number greater than one and that’s going to give you your horsepower so for example say we’re looking at 10,500 for rpms that your cars revving at pretty high but I’m just doing this for simplicity so you’re going to have 10,000 54 times your torque divided by 52 52 so your horsepower is going to be twice your torque at that rpm that will always be the case so at 5252 your horsepower then becomes greater than your torque and that doesn’t necessarily mean though that your torque will be going down they could both still be increasing but your horsepower is going to be greater than your torque once you pass 5252 and it will be less than your torque below 5252 um so what does this mean horsepower versus torque a good analogy just let’s just look at two engines so we’ve got a truck and a sports car the truck has a lot of torque but it’s low revving so it’s got low horsepower but it’s very strong a sports car has lower torque but it’s very high revving say 8,000 9,000 rpms so it’s got high horsepower but it’s weak now you can have a little analogy with um say a bodybuilder and a sprinter think of a bodybuilder as a lot of torque so say you put 50 pounds in a backpack on a bodybuilder and tell me run 100 meters he’ll run it in about the exact same time that he ran 100 meters without the backpack now Taylor sprinting around 100 meters and then put a 50 pound backpack on the Sprinter it was weaker and just built for moving fast and it’s got really going to affect his time so that’s a good way of looking at it as if you add weight to a sports car or a high revving low volume engine say like a 2-liter turbo it’s really going to affect its performance it’s not gonna be able to accelerate whereas you put a thousand pounds in the back of a truck it’s still going to accelerate relatively at the same rate

I want to see the new and improved version of this video….people have been trying to understand HP and Torque forever!

Can you make videos with Metric numbers? The Metric systen is way more logical anyway

this is an old video, you should redone and I'm sure u will get way more views, and the video will have better quality

so weight reduction in a sports car is very effective to make it faster?

Is there a simple conversion for Horsepower to KiloWatts and/or Ft.pounds to Neuman Meteres?

Why is it that on these engine specs I see online it says that the peak torque happens at some rpm lower than the peak power?

Does the torque actually decrease past a certain rpm or does it just plateau?

hello everyone and welcome I wanted to say that jason fenske is the best engineer youtuber with high quality videos( except this one ;-). Give him a sub. You won't be disappointed.

OMG it all relates to each other and I can understand. Thanks!!! Physics is so cool.

Can you explain how some engines of the same kind(inline, v type, boxer etc) presents variations of torque according to number of RPM? I mean: some have high torque at low rev, whereas others of the same kind have high torque at higher revs. what is the trick?

I like your channel so much.. You're doing good…

Your presentational skills have improved considerably since you made this video. It isn't bad or wrong, but it could be clearer. I agree with the commenters who suggest that this video would benefit considerably from a remake, with some thought given to explaining horsepower and torque, and then the relationship between them.

Hey kid, no replacement for displacement.

I've seen some really great explanations by this guy, particularly in more recent years and was hoping to find a good explanation on the difference from him, but his example of adding weight was entirely off base. Acceleration = force/mass. That means that if you double the weight, the acceleration will be half, period. Force of thrust at the rear wheels at any given speed will always be proportional to the horsepower. Thus, acceleration and weight will be inversely proportional. I would love to see him revisit this topic in the future.

how i can get a theoretical top speed from the total horsepower of my bike?

Thanks for the video. I would still like to understand why cars vary so much in hp/torque numbers. For example, a 2015 Ferrari 458 has 570 hp/398 lb-ft while a 2015 Corvette has 460 hp/460 lb-ft and a 2017 Mercedes S550 has 449 hp/516 lb-ft. Why are 458's numbers so disparate while the Corvette's are exactly the same. And why does the S550 have more torque than power? It would be nice to explain in a video why different cars have the hp/torque numbers they make. Thanks!

Please explain to me how did you came up with 5252 instead of 33000?

I know it's a tad late to say, but it'd be nice to also mention the units of the metric system. Nice video!

Honesty I find this concept difficult to comprehend but your example is the best I've seen so far, especially the trunk/bodybuilder sportscar/sprinter analogy. Thank you.

AWESOME VIDEO

exceptional video. well done

so torque is for acceleration and hp for speed?

I have a 5.7L LS1 engine that is rated @ 350 HP and 350 ft. lbs. torque. What is the benefit of this close relationship?

good job

I love the old videos

90 hp

Now I'm gonna need a calculator whenever I press the gas pedal.

Engines HAVING HIGH TORQUE Have The Ability To Spin The Crank Shaft SLOWLY, While There Is MUCH RESISTANCE Being Applied To The Crank Shaft To Impede It From Spinning! If we leave everything out of the conversation except for engines, and the crank shafts are protruding from different engines, and the protruding portions of the crank shafts are all the same diameter, and all the C/S have identical cables attached to them dangling down ten feet, it's MY understanding that the engine with the Most Torque can lift the Heaviest cube of lead attached to the bottom of it's cable AT SLOW SPEED!!!!! Say One Quarter of a Mile Per Hour.

Soooo complicated to me and i'm not good in math lol

youre awesome bud…. i watch your videos often and am always impressed with your ability to explain things so the average person can understand it.

Bodybuilding Sprinter.

Do we need the boring math for this? Plenty of mechanics do this without math.

great job

2:17 "your horsepowers become greater than your torque" you cant really say that, because they are two "completely" different units, its like saying 60 meters is greater than 50 seconds or 10kg is greater than 5 celcius degrees. See, doesnt make a lot of sense. Theyre just numbers and even though power and torque are related to eachother doesnt mean than you can say one is greater than the other

i thought horse power was how many horses ur car was going fast as loooooooooooooooooooool

Great video, man!

Thank haShem for the Hebrew subtitles – lest we all be lost.

Hebrew… HELL YA!!! Power to my people!! #LeastJewishNameEVER

The combination of Torque x rpm or HP vs rpm is the most important thing. Torque x rpm tells you how the engine delivers the power – the same HP can be delivered by one engine with lots of torque, but at lower rpm, or by another engine with less torque, but which spins faster. At the same rpm, the engine producing more torque is producing proportionately more HP as well, and this what is referred to as "torquier". And this is the reason why we have gears in the first place. Most engines would have to be impractically powerful to give both acceleration and speed in the same gear, so gears adjust the ratio to give you more acceleration in lower gears, and more speed in the higher gears. However, the engine HP is the same.

However, a high revving, lightweight engine would be better suited for lightweight vehicles, while an engine spinning slowly, but producing more torque would be suited for heavy duty work. If you try it the other way round, you will end up with too many gears and too much shifting, making them impractical. A lightweight engine may also not be able to withstand the stress of too much torque, while a heavy engine would not have quick response and might burn far more fuel than it needs to.

So basically horsepower is how fast torque does its job?

Hey bud! Two Video ideas.

1. Obviously we know dyno will read drastically different depending on brand, location, and environment variables. I know many people say you can accurately measure real hp by a cars et or trap speed calculated against its weight. Nobody has been able to accurately explain the math on this. There are variables on changing gearing to accelerate faster would change your hp calculation.. but there MUST be a way to calculate this.

Second. I think motor trend did a video back in the day but I can’t find it.. explaining why in a standing mile.. starting from a stand still vs starting at 60mph, or any speed for that matter,… your end speed really doesn’t change. I’ve seen this at the track with roll race events vs dig races. My et is obviously faster but my trap speed maybe increases by 1mph. Doesn’t matter if I’m doing 20…60..80… or whatever to start.

I think the first idea would be awesome for helping people figure out a more accurate way to compare friends actual hp numbers.. would be cool.

Jason love your explanations. I have learned so much. Please ignore the intellectually challenged Neanderthals who over simplify your rules of thumb. Pity they don't understand you are generalizing complex technology into bite sized pieces and there are exceptions to every rule.

What happened to common sense?

Wish I could think at 0.5x as fast as you!

Thanks for taking the time to pass on your valuable Knowledge.

Lol watching this in 2017 – you look so young. I see the whiteboard has improved a lot!

Here's a good way to understand how Torque & Power relate to a vehicle acceleration: In first gear, your vehicle accelerates greater than in top gear. Why? Because through torque multiplication, more torque is applied to the wheels.

Peak Power is a calculation indicating how long the useful torque can be maintained in a particular transmission gear.

Eg. A typical turbo diesel engine produces large torque at low rpm but can not maintain the acceleration for long due to a low peak power, so the transmission gear must be changed to continue accelerating. This can be offset by reducing overall gearing to extend time between gear shifts at the expense of acceleration.

Do you have a video that explains "Powerband" of a car?…just because i'm sure you'll explain it in a "scientific" way for a nerd like me. What does the common point in your graph?

I have long known the equations. Reality hit home when I had a slipping clutch. Going up a modest hill in fourth (high) gear at 50 mph, the clutch began to slip. Dropping into third gear the car could maintain speed without overstressing the clutch. Higher RPM but lower torque was producing the same horsepower (hence climb speed) without exceeding the torque the clutch could handle.

In real situations, forget the fudge factors; just remember that power equals torque times RPM.

hey i got a 95 f150 lariat with a 5.0 and im wanting to add higher end power without completely building the motor so what should i add to make the most power on a budget

My seat of the pants experience tells me that torque is more of the velocity of air that flows through the engine while horsepower is more equivalent to the volume of air that is moving through the engine. I ideally you want just enough torque to move your mass, As too much of it requires more durable, Heavier, more expensive parts, and shreds tires. A transmission can Even out any deficit of torque Through a given stretch of road or racetrack. Watch a Corvette ZR1 race a Ferrari 458 Italia. Not only does a Ferrari Rev much much faster but the Corvette will struggle to put down Rubber without losing traction In the technical sections. Sometimes you can fix this with a Numerically higher gear ratio. But doing so can create a sewing machine effect and Require an infinitely patient finesse To tiptoe up to speed.

Wow such an old video

I have a question: in a Hp/Torque graph what's on the y axis?

Nice 🙂

the supreme gentleman

Awesome Video man Thanks! What would be the difference if I got a car that has more torque than horsepower? Or vice versa? Does that affect my 0-60 times also?

what the hell is a footpound

You didn't explain this topic too good

So, with the proper gearing, and the same weight and traction, which is faster accelerating? high HP low torque, (say 500 and 250 respectively), or low hp high torque (say 250 hp and 500 lb/ft)?

I say low, 250 hp is a lot for a average family car, I know

Horsepower is how fast you hit the wall, torque is how far you take it with you.

I guess the math is correct but I know that the HP and Torque produced by an engine will vary and depend on a lot of factors:

bore vs stroke measurements (oversquare engines rev higher and tend to produce more HP and less torque)

Compression ratio (as related to volumetric efficiency?)

Valve timing as decided by the camshaft design

etc

Yes an old video, but a a good one 😀 Thanks!

Please explain about of integrated starter generator in next video

Torque: How hard you get pushed back in your seat.

HP: How long you get pushed back in your seat.

😀

Has a cyclist more torque in low RPM? As much RPM can you move the legs, do you have more power?

Thanks 🙂

I like your explanation but these pounds, foot, etc. are driving me crazy

As clear as mud

Hi

I have a question about power and torque

I understand 90% of it but one thing i dont understand.

If for better acceleration we need power not torque, so why in my car 1.8t chipped i feel better acceleration for example on 3rd gear betwen 2,5k-4k rpm (where average power and torque is 135hp & 290Nm) than between 4,5k-6k rpm (where average power and torque is 180hp & 240Nm) ??

I know there is a air resistance but i dont belive that is so big. Same feeling on 2nd gear.

Same example is in diesel 1.9tdi 130hp.

On 3rd gear at 4k rpm (max power) accelerate slower than at 2.5k rpm

All I want to know why I fell more counter force on my seat when I 'am betwen 2.5k-4k RPM than between 4,5k-6k RPM although power of engine is bigger there

Why is that?

it's really simple and I don't know why these assholes make it hard. TQ= REAL POWER, SPEED, ACCELERATION and so on. to build HP you need more TQ so therefore TQ is doing all the work. TQ is the twisting force of the crankshaft and a engine can't operate without TQ at ANY rpm. HP= (TQ)X RPM so HP is TQ also jus at higher RPM but it's still TQ doing all the work. HP can't do a damn thing without TQ but TQ can do alot without HP.

This was the best video I’ve seen explaining horsepower and torque thank you

nicely explained

Is this same formula used with bikes too? Meaning, my 675 Daytona redlines at 14,000.. that means everything after 5252 is going to be more power than torque and I’ll have more than double my power vs. torque at anything above 10,504 rpms.. is that correct?

Perfect example why weight reduction is just as important as engine performance, excellent video.

I’m that bored

is he wearing a nazi helmet?

hello maybe I took this in wrong but ok so say two cars have the same horsepower same weight same amount of cylinders but one has more torque wouldn't that make the car with more torque faster I know in higher altitudes that cars with similar horsepower and weight but one has more torque the car with more torque will usually win I saw this in a fastlane video it was a Scion tc vs a frs the tc had more torque but a little less horsepower but it won in a quarter mile so would it be the same in the scenario I gave thanks

New Genesis data has their highest torque engine has its lowest horsepower, rpm measure is fixed. For rpm is fixed wouldn't hp and torque be directly proportional ?

So glad he got rid of his mop top.

dude, every time i have a question about car stuff, i type it into the search bar on youtube, and you are always one of the first search results. thank you. i'm clearly the target demographic haha

just wondering if you done a thing of max torque or hp you can apply to road before losing any (I am wondering when you start to lose it)

a technical question … can you perceive a torque difference of 4nm? that is, a motorcycle of 30nm against a motorcycle of 34nm

WOW Scientific video without using the metric system we meet again!

Using your analogy would it be right to understand that the sprinter would get gradually faster over the race and if it were long enough would win given the higher power output over the whole race?

Boring

As of today which is 10/30/18 I'm officially not cursing anymore. I want to become a Christian

Hahahaha can we please get a v2.0?

well then how much torque does my tractor make at 35 horse & 1680 RPM

This kid needs mit or sum shot

Love these videos bro 🤙

The two "Engineering Explained" videos "Horsepower vs Torque…" are good, but as a complete novice I can tell you that the explanations are far too comprehensive, as are most explanations on the internet, for a rank beginner, like myself.

Just as physics/electronics teachers often use unrealistic simplistic examples to get a basic point across ("imagine a perfect vacuum" "disregarding line losses", etc.)…after reading online many explanations of torque vs. horsepower that go on and on, getting bogged down in details, I think that some of us need a more simplified (as simplified as possible) explanation at first, so that we don't get lost in the details before we even understand the basics.

I know the following example is not at all realistic, but once the discussion starts to include any factors or numbers beyond HP =T x RPM, I quickly get lost. Is this statement (by me) correct?:

If two cars driven by equal drivers are of equal weight, and drag/friction forces are equal on both cars, and both cars are able to equally efficiently deliver their horsepower to the driving wheels at all times, and both cars rpm's are held at their maximum horsepower rpm's for the entire duration of the race, the car with the higher horsepower rating…regardless of how little torque it is capable of achieving…will always win any race/drag of any kind.

If the above statement is true, then I would say that the best way to explain torque vs. horsepower to someone like me who just "isn't getting it" would be to start with HP =T x RPM, and then explain that if we had a way of 100% efficiently and economically delivering horsepower to the driving wheels at all speeds, then torque values and graphs would be irrelevant to the driver, because an engine's maximum horsepower rating and at what rpm it will be achieved would then be all that the driver would care about to win any kind of race, including very short drag races (100 feet, for example). The driver wouldn't need to know the torque values, he/she would only have to know the maximum horsepower rating, and at what exact rpm it will be achieved, so that he could hold the rpm at that exact value for the duration of the race. And engines could be designed solely for maximum horsepower, without regard for torque.

And, therefore, the only reason that torque values and graphs are currently relevant to the driver is because we don't have this 100% efficient way to deliver horsepower at all speeds, and so therefore, to win drag races or other races where we cannot keep the engine at or near max hp rpm most of the time, we have to design engines with low-end torque in mind (even though it sacrifices horsepower in the engine design).

And then, after the student has grasped the basics above, THEN the instructor could proceed to explain all of the OTHER factors that make running at max hp rpm either impossible or impractical, and how designers and drivers deal with all of these other factors.

I disagree. You said that a body builder will run the same time with the 50lbs and without the 50lbs, on his back. That just isn't correct. According to Newton's second law, which relates force, mass and acceleration in the equation force (F) equals mass (m) times acceleration (a), written as F = ma. If you solve for a, then you have a=F/m. This means that the acceleration has to be different with more mass, or weight. Since torque is not a force, but a quantity of work, and hp is a Force, therefore, hp is the Force in our case. So, a=hp/weight. So, in final, its not torque that matters in acceleration, its the hp that matters. Or rather hp is the the amount of work (Torque), in an amount of time elapsed. Same thing as your equations. BUT, and most importantly, its the hp that matters at a given time. So, its the instantaneous hp that matters. When a truck takes off from a dead stop, what instantaneous hp is it using? When a sports car takes off from a dead stop, what instantaneous hp is IT using. The rpms are low, and the truck is using an instantly high amount of hp relative to the sports car. The sports car must rev up his engine to get the same hp that the truck is using at low rpm. This is why a truck can pull alot from a dead stop and a car cannot. But, if you sling shot'ed the truck and sling shot'ed the car, and they were both going 40mph, then the truck could use his advantage of hp at low rpms [by putting in the proper gear], and the car could use his advantage of hp at high rpms [by also putting it in the proper gear]. Then, it would be a true test of who could pull more and has more hp at those speeds… But, that's not what a truck is made for, nor what a sports car is made for. The truck is made to pull at low speeds, and the car is not made to pull at all.

PS. In my example of the truck vs the car, at 40mph, the car would win, just a side note. The car clearly has the hp, and it weighs next to nothing compared to the truck. But, if its pulling something heavy, it might just yank the rear end right off, since the body isn't made to handle it. That's why the truck is heavy, so it doesn't fall apart when it tries to pull something heavy.

There you have it, hp vs torque explained. Look out for my video.

If 2 cars have the same 0 to 60 speed but one has more hp and torque than the other has does the car with more hp/torque feel better or more sportier to drive?

What's a good torque curve for diesel engines? Max torque at 2k rpm then steep down or starts medium torque at 2k rpm then goes up max to 3k rpm then slowly goes down from there.

that number, 5252, is a reference, as rotation per minute, ONLY in one scenario: 1 pound over 1 foot lever arm… other than that, WHICH ALWAYS HAPPENS, is useless. so, what's so magical about that number? nothing… it's just a reference for one scenario only.

Basically for ease of driving ie everyday use. Get a car with a lot of low down (low down the rev range) toque. For racing about like a loon, higher reving horse power. Put in manufacturing terms Merc AMG or BMW M…

Review Nissan Skyline V36 VQH Engine, the G25 and G37 models

Would this apply for electric motors?

How to clean a Diesel Particulate Filter (DPF)

Very well explained buddy….I got it…..

When a car company lists the "peak torque", how is that measured? Is that coming off the wheels or somewhere else?

Whether you are towing a trailer or drag-racing a car, horsepower is what will determine acceleration. Ironically this is because torque at the tires is what applies force to the ground, but using torque at the flywheel requires the drivetrain gear ratio from the flywheel to the tires. Horsepower does not change with gear ratio. The body builder vs sprinter analogy isn't my favourite since it doesn't compare which one is actually doing more work (force x distance). By definition higher horsepower is doing more work. People relate high torque engines to being good at towing because they are high horsepower in the lower drive-able rpm range.

0:43 incorrect. power is measured in work per unit time, not torque per unit time. lb ft is a measurement of work as well as torque, but that does not mean theyre the same thing

Torque is King on the public streets. Acceleration, not intending to go 100 miles an hour. Leaving everyone behind at the lights is torque. Class dismissed.

When you get up in the morning with a piss hard on. You go to the toilet and bend it down and your feet slide out from under you. THAT'S TORQUE!

whic is much better when in terms of fuel efficiency? if HP i need to press the gas pedal longer to gain power. if T i just need to press the pedal a little to gain power so i can switch up to next gear really quick since it was more efficient to ride in a higher gear.

Metric please