Power vs Torque: What’s the difference?

If you’ve read anything about cars, the chances are that you’ll have come across the words ‘power’ and ‘torque’. But if you’ve seen journalists ranting about the torque of a 4×4’s diesel engine and wondered what on earth they’re on about, then read on…

So what is torque?

Bear with us, because this is quite complicated.

Forgetting cars for a second, a physicist would describe torque as a twist. If you use a wrench to undo a nut (as in a nut and bolt, not a walnut), you’re applying torque. You’re twisting the nut to undo it.

But if you break it down even further, what you’re effectively doing is applying force to a point some distance from the nut. That’s why torque is measured in terms of ‘force x distance’ – Newton-metres (Nm), for example, or pounds-feet (lb-ft). So if you apply 10 newtons of force to a point one metre from the nut, the torque on the nut will be 10 newton-metres (10Nm).

In a car’s engine, though, the twisting force is applied to the crankshaft. The piston is connected to a hinge that’s a certain distance from the centre of the crankshaft, and as the piston moves up and down, it pushes the crankshaft around. Multiply the force of the piston by the distance of the hinge from the crankshaft, and you’ve got torque.

Jaguar Diesel Engine Diagram
A diagram of a four-cylinder Jaguar diesel engine, showing how the piston (centre) turns the crankshaft (bottom)

What is power, then?

According to physicists, power is the rate at which work is done. In automotive terms, that’s how quickly an engine can apply its torque.

A simple one-cylinder engine with 10Nm of torque would apply 10Nm per engine revolution. If it can manage 1,000rpm, it’ll apply those 10Nm of torque 1,000 times per minute (10,000Nm per minute). If, on the other hand, it can do 2,000rpm, it’ll apply 10Nm of torque 2,000 times a minute (20,000Nm per minute), making it more powerful.

Because of the industrial revolution, we measure power in ‘horsepower’, which makes its meaning less obvious. One metric horsepower is the torque needed to lift 75kg one metre in one second using a pulley. Force, speed and distance are all in there, but they needed a unit that resonated in the 1800s. Complaints should be addressed to the Victorians.

Right… I get the science, but why does this matter to a driver?

Although torque and power are closely related, they feel slightly different on the road. In simple terms, and assuming all other things are equal, torque is what gets you moving at lower engine speeds, whereas power gets you up to speed when you put your foot down.

McLaren 570S Spider 2017 Blue Rear Dynamic

Which is more important?

That depends what you want, really. In a 4×4 that needs to get out of sticky, cloying mud, but doesn’t need to go very quickly, then torque is ideal. Alternatively, power would be more important to a sports car that needs a high top speed.

Which engines have the best performance?

Generally speaking, diesel engines will have more torque than petrol engines of the same size, while petrol engines will have more power than their diesel rivals. Because of the properties of the two fuels, petrol engines are capable of more engine revolutions than diesels, while diesels can apply the piston’s force further from the centre of the crankshaft.

That’s why big, heavy 4x4s tend to have diesel engines, while supercars use petrol. It’s also why, during everyday use, people often think diesels are faster than petrols. It isn’t necessarily true, but a petrol will have to work harder (i.e. spin faster) to provide the same performance as an otherwise identical diesel.

For the best acceleration, though, you’ll probably need an electric motor. Whereas maximum torque in a diesel engine is usually around 1,500-2,000rpm, an electric motor provides maximum torque at all times. That’s why the Jaguar I-Pace and Tesla Model S accelerate so quickly.

Jaguar I-Pace 2019 Grey Front Dynamic

 

51 thoughts on “Power vs Torque: What’s the difference?

  • June 15, 2019 at 1:33 am
    Permalink

    Nice post. I study one thing tougher on totally different blogs everyday. It should always be stimulating to read content material from other writers and observe slightly something from their store. I’d favor to use some with the content material on my blog whether you don’t mind. Natually I’ll provide you with a hyperlink on your net blog. Thanks for sharing.

    Reply
  • June 22, 2019 at 1:43 am
    Permalink

    Heya! I just wanted to ask if you ever have any problems with hackers? My last blog (wordpress) was hacked and I ended up losing several weeks of hard work due to no backup. Do you have any solutions to stop hackers?

    Reply
  • June 22, 2019 at 8:31 am
    Permalink

    Hey! This is kind of off topic but I need some guidance from an established blog. Is it hard to set up your own blog? I’m not very techincal but I can figure things out pretty fast. I’m thinking about creating my own but I’m not sure where to begin. Do you have any ideas or suggestions? With thanks

    Reply
  • June 22, 2019 at 9:52 am
    Permalink

    Good info. Lucky me I reach on your website by accident, I bookmarked it.

    Reply
  • June 23, 2019 at 8:22 pm
    Permalink

    Hi! I know this is kinda off topic but I was wondering which blog platform are you using for this site? I’m getting tired of WordPress because I’ve had problems with hackers and I’m looking at options for another platform. I would be fantastic if you could point me in the direction of a good platform.

    Reply
  • June 23, 2019 at 9:35 pm
    Permalink

    It’s appropriate time to make some plans for the longer term and it is time to be happy. I’ve learn this put up and if I may I wish to recommend you some interesting things or advice. Perhaps you can write subsequent articles referring to this article. I wish to read even more issues about it!

    Reply
  • June 23, 2019 at 10:46 pm
    Permalink

    An fascinating dialogue is worth comment. I think that it’s best to write more on this subject, it might not be a taboo topic however usually individuals are not enough to talk on such topics. To the next. Cheers

    Reply
  • June 24, 2019 at 4:01 am
    Permalink

    I’ve been exploring for a little bit for any high-quality articles or blog posts on this kind of area . Exploring in Yahoo I at last stumbled upon this web site. Reading this info So i’m happy to convey that I have a very good uncanny feeling I discovered exactly what I needed. I most certainly will make sure to don’t forget this website and give it a glance regularly.

    Reply
  • June 25, 2019 at 5:37 pm
    Permalink

    x3oQqQpfwnpVjpdqgh3LXqLFadPe4q3C6LZjtLKZfPzcHCfvmqIwTRypqxuFJ7p0xgHnjCV

    Hi, very nice website, cheers!
    ——————————————————
    Need cheap and reliable hosting? Our shared plans start at $10 for an year and VPS plans for $6/Mo.
    ——————————————————
    Check here: https://www.good-webhosting.com/

    x3oQqQpfwnpVjpdqgh3LXqLFadPe4q3C6LZjtLKZfPzcHCfvmqIwTRypqxuFJ7p0xgHnjCV

    Reply
  • June 26, 2019 at 6:21 am
    Permalink

    I’ve been browsing online more than 3 hours today, yet I never found any interesting article like yours. It’s pretty worth enough for me. In my view, if all web owners and bloggers made good content as you did, the internet will be much more useful than ever before.

    Reply
  • June 27, 2019 at 5:44 am
    Permalink

    I have been browsing on-line more than 3 hours nowadays, but I never discovered any attention-grabbing article like yours. It is lovely worth sufficient for me. In my opinion, if all site owners and bloggers made just right content material as you did, the net will likely be much more helpful than ever before.

    Reply
  • June 28, 2019 at 6:40 am
    Permalink

    Some genuinely great info , Sword lily I detected this. “Good teaching is one-fourth preparation and three-fourths theater.” by Gail.

    Reply
  • June 28, 2019 at 7:17 am
    Permalink

    This is a very good tips especially to those new to blogosphere, brief and accurate information… Thanks for sharing this one. A must read article.

    Reply
  • June 28, 2019 at 7:54 am
    Permalink

    I’ll immediately grab your rss feed as I can’t find your e-mail subscription link or newsletter service. Do you’ve any? Kindly let me know so that I could subscribe. Thanks.

    Reply
  • July 3, 2019 at 6:52 am
    Permalink

    Way cool, some valid points! I appreciate you making this article available, the rest of the site is also high quality. Have a fun.

    Reply
  • July 8, 2019 at 9:17 am
    Permalink

    Howdy! Quick question that’s completely off topic. Do you know how to make your site mobile friendly? My web site looks weird when viewing from my iphone4. I’m trying to find a theme or plugin that might be able to resolve this issue. If you have any suggestions, please share. Cheers!

    Reply
  • July 8, 2019 at 10:29 pm
    Permalink

    It’s actually a cool and helpful piece of info. I am glad that you shared this helpful information with us. Please stay us up to date like this. Thank you for sharing.

    Reply
  • July 9, 2019 at 3:16 pm
    Permalink

    Hello there, I found your site via Google while looking for a related topic, your website came up, it looks good. I have bookmarked it in my google bookmarks.

    Reply
  • July 14, 2019 at 11:00 pm
    Permalink

    Those are yours alright! . We at least need to get these people stealing images to start blogging! They probably just did a image search and grabbed them. They look good though!

    Reply
  • July 15, 2019 at 6:47 am
    Permalink

    You could certainly see your enthusiasm in the work you write. The world hopes for even more passionate writers like you who are not afraid to say how they believe. Always follow your heart.

    Reply
  • July 17, 2019 at 5:55 am
    Permalink

    Right now it appears like Expression Engine is the top blogging platform out there right now. (from what I’ve read) Is that what you’re using on your blog?

    Reply
  • July 19, 2019 at 5:37 pm
    Permalink

    The core of your writing whilst appearing reasonable at first, did not really work properly with me personally after some time. Somewhere within the paragraphs you actually managed to make me a believer unfortunately only for a while. I however have got a problem with your jumps in logic and one would do nicely to help fill in all those gaps. When you actually can accomplish that, I could definitely end up being fascinated.

    Reply
  • July 20, 2019 at 11:34 am
    Permalink

    Very interesting topic, regards for putting up. “All human beings should try to learn before they die what they are running from, and to, and why.” by James Thurber.

    Reply
  • July 20, 2019 at 5:11 pm
    Permalink

    Hi, i think that i saw you visited my blog so i came to “return the favor”.I’m trying to find things to improve my web site!I suppose its ok to use a few of your ideas!!

    Reply
  • July 20, 2019 at 5:40 pm
    Permalink

    After examine a couple of of the weblog posts on your web site now, and I truly like your way of blogging. I bookmarked it to my bookmark web site listing and will likely be checking again soon. Pls check out my website as nicely and let me know what you think.

    Reply
  • July 21, 2019 at 5:39 pm
    Permalink

    I truly appreciate this post. I’ve been looking all over for this! Thank goodness I found it on Bing. You have made my day! Thank you again!

    Reply
  • July 22, 2019 at 9:59 am
    Permalink

    I’m curious to find out what blog platform you’re using? I’m having some small security issues with my latest website and I’d like to find something more safe. Do you have any suggestions?

    Reply
  • July 22, 2019 at 2:47 pm
    Permalink

    Great write-up, I’m regular visitor of one’s blog, maintain up the excellent operate, and It’s going to be a regular visitor for a lengthy time.

    Reply
  • July 24, 2019 at 8:17 am
    Permalink

    Wow, marvelous blog layout! How long have you been blogging for? you make blogging look easy. The overall look of your web site is wonderful, as well as the content!

    Reply
  • July 24, 2019 at 1:56 pm
    Permalink

    I haven¦t checked in here for a while since I thought it was getting boring, but the last few posts are great quality so I guess I will add you back to my daily bloglist. You deserve it my friend 🙂

    Reply
  • July 24, 2019 at 2:45 pm
    Permalink

    Hi! I could have sworn I’ve been to this website before but after reading through some of the post I realized it’s new to me. Nonetheless, I’m definitely delighted I found it and I’ll be bookmarking and checking back frequently!

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *