HP or Torque

[The Artist]

ohh are there more reasons why you love amg ?

[MikeJ]

Torque to me, baby!

[Matt]

I also voted torque. I love that grunt that gets you out of jams. Its a pretty awsome feeling although most journalist would have one think HP is more important for some reason.

[martinbo]

Yes yes, of course torque is the more important of the two. But then again there are some interesting things to be aware of in a discussion such as this. Interestingly, I voted for HP because, after all, HP is torque x rpm or the rate at which the torque is delivered within the rev-range of an engine. However, a simple fact of life remains: without torque there can be no power.

I am more interested in the relationship between torque and power rather than single point data on a graph or spec sheet. Imagine if AMG's twin-turbo V12 only revved to 3000 rpm - it'd make that vital 1000 Nm but wouldn't quite get to delivering the speed that it is capable of in reality. This is because all that torque is not delivered quickly enough for long enough. That's why a modern turbo diesel is invariably slower than its petrol equivalent in an outright sprint but is quicker in mid-gear acceleration.

The same of course could be said for putting an F1 engine in a big saloon, it may have 600 kW of power but the lack of torque means that it would really battle in overcoming or moving that large mass before, eventually, reaching the "working zone" of the rev range.

So yes, I'm going to be the odd one out: you can have all the torque you want but if you don't deliver it at the right rate then it's pretty useless for performance motoring so I'm going to vote for HP.

Very nice poll.

[Snake Vargas]

Hmm. Torque and power aren't really exclusive things, though I suppose I'll have to try not to make it out that those who voted for one are saying that at all.

What I'm nost concerned about is adequate torque at adequate revs, and for a reasonably wide rev range. To that extent, I suppose torque is the more relevant for my everyday driving, but I always look at what revs it's produced at, in the abesence of an actual torque/power/rev graph (why don't manufacturers give us those?).

Power is important enough, but only as a secondary measure. It's not that hard to produce high power numbers with a little bit of careful engineering and pumping up the revs and tuning the engine to produce torque higher in the rev range. But that's only good if you like actually driving in that rev range to access the performance.

I was almost going to skip the poll.. and Martin once again makes some good points.. but I'm going to make it a qualified vote for torque, since that figure is overall more what I look for than peak power, but I'll still be looking for what rev range they're produced at, and more importantly, the butt dyno is probably the ultimate measure.

[Matt]

So, HP is how fast the engine can deliver a certain amount of torque. So if you have a high horsepower engine and a low torque engine the engine haves to move much faster to get the same hp. Very interesting. Thanks for the technical insight Martin.

[martinbo]

Originally Posted by Matt is bomb

So, HP is how fast the engine can deliver a certain amount of torque.

Exactly. Horsepower is, interestingly, a calculation as opposed to a measurement.

Originally Posted by Matt is bomb

So if you have a high horsepower engine and a low torque engine the engine haves to move much faster to get the same hp. Very interesting.

Precisely the philosophy practiced by BMW's M division. Their ethos is the pursuit of good power in high revving engines without having to compensate and compromise for too high a torque delivery which puts great strain on transmissions, clutches, differentials, prop shafts and so on. The strain placed on these components necessitates significant strengthening and this invariably leads to heavier items.

Imagine how much strain the Veyron's 1200 Nm exerts on these components and you get an idea of why the car is almost twice as heavy as an F1.

Furthermore, the M5's rather modest (it's actually not modest at all) torque output compared with forced induction rivals is actually an advantage in that it combines well with the SMG III gearbox without requiring unnecessarily weighty modifications. And, of course, therein lies another of the M5's trump cards: a gear ratio is a torque multiplier and the M5 has 7 of them. What this means is that, because the engine revs so high, the gear ratios can be shortened* thus multiplying the torque at the wheels whilst still enjoying high top speeds in each gear courtesy of the 8250 rpm rev range. Brilliant. Motorsport technology for the wealthy(ish) man on the street and that's just one of the things that makes this new M5 such a technical tour de force.
[Pity, then that it guzzles gas like a camel that's been out in the desert for a month - but hey, if you want those horses then you must feed them.]

Originally Posted by Matt is bomb

Thanks for the technical insight Martin.

You're most welcome. Eventually, bear in mind, I will reach my level of technical incompetence and you'll have to direct your questions to an engineer.

* Saying that the gear ratios are shortened is actually a misnomer but it's so commonly used in modern car speak that it's become acceptable. In fact, the larger the ratio of geared output vs input, the shorter the gear in driving. i.e. first gear has a bigger ratio "4.35:1" than sixth gear "0.95:1"

[Michael]

Originally Posted by Audi4Life

You know what they say....torque wins races.

HP sells cars, and Torque wins races

[Imhotep Evil]

Both if posible, the M way if not.

[Audi4Life]

Originally Posted by martinbo

Exactly. Horsepower is, interestingly, a calculation as opposed to a measurement.



Precisely the philosophy practiced by BMW's M division. Their ethos is the pursuit of good power in high revving engines without having to compensate and compromise for too high a torque delivery which puts great strain on transmissions, clutches, differentials, prop shafts and so on. The strain placed on these components necessitates significant strengthening and this invariably leads to heavier items.

Imagine how much strain the Veyron's 1200 Nm exerts on these components and you get an idea of why the car is almost twice as heavy as an F1.

Furthermore, the M5's rather modest (it's actually not modest at all) torque output compared with forced induction rivals is actually an advantage in that it combines well with the SMG III gearbox without requiring unnecessarily weighty modifications. And, of course, therein lies another of the M5's trump cards: a gear ratio is a torque multiplier and the M5 has 7 of them. What this means is that, because the engine revs so high, the gear ratios can be shortened* thus multiplying the torque at the wheels whilst still enjoying high top speeds in each gear courtesy of the 8250 rpm rev range. Brilliant. Motorsport technology for the wealthy(ish) man on the street and that's just one of the things that makes this new M5 such a technical tour de force.
[Pity, then that it guzzles gas like a camel that's been out in the desert for a month - but hey, if you want those horses then you must feed them.]



You're most welcome. Eventually, bear in mind, I will reach my level of technical incompetence and you'll have to direct your questions to an engineer.

* Saying that the gear ratios are shortened is actually a misnomer but it's so commonly used in modern car speak that it's become acceptable. In fact, the larger the ratio of geared output vs input, the shorter the gear in driving. i.e. first gear has a bigger ratio "4.35:1" than sixth gear "0.95:1"

holy crap...ure afrakin' genius...