What's the difference between power and torque of a car ?

Hi All,

This thread had been one of the most informative ones I had ever read.  Thanks for all the inputs.  Just bowled by the way Nic and Narayana Pai are able to link technical stuff to what one just feels behind the wheel!

Not sure if this is the right forum, but I am interested in going to further details... to be precise, technical.  I want to study and understand power band and power delivery graphs.  Can someone suggest good sources of information?  Some links would do a great favor.

Thanks in advance, and sorry for (almost) hijacking this thread

Regards,

SKB

Exactly what i was looking for. Thank you very much for the info.

For me torque is a more important consideration in a car than power. In that respect I love diesel cars life Swift. I love the torque kicking it and pushing it forward in the 4th gear.

Himanshu, In the above lines you have given 99% marks to getz but in last line u said i10 us a better performer than getz. Whats the logic behind this?

Thanks for all, for making this thread so useful i really appreciate and now i am clear about power and torque.

even I used to think like that..I have a diesel (linea) and a petrol (swift), when I have 4 person and want to reach 80-90 km/hr quickly linea is superb as it produces much more torque (same 87 bhp like swift petrol but with much higher torque) but after 140-150 km/hr refuses to climb further...where as swift with less passenger is much faster goes to higher speed at a faster rate after 120 km/hr.

To be precise diesel is very good for the intial pickup  (with or without load) and moderate speed upto 110/120, but after that you cannot beat a petrol car.....

I used to think that Torque is what caused a car to accelerate, mostly because the word itself sounded so ultra-techie and fancy. This, of course, was when I was still drooling over the design rather than what was under the hood of a car. From what I've come to understand, an engine's Torque peaks early and then falls away gradually whereas its Power keeps climbing long after the engine has reached its peak Torque. By that time, the combustion process has stopped working efficiently because the engine has gone as high as it will go.

The cars that have the highest rate of acceleration are dragsters, simply because they produce incredible amounts of torque that make their power outputs outclass the F1 cars. This of course makes them highly volatile and unreliable, coffins on wheels as far as I'm concerned. Those are definitely cars that I will stay far away from but will continue to dream about. All this ranting was basically to say that don't get carried away by fancy terms like I used to. The power of the engine is the most important aspect of any car.

pankaj,

How to start a new forum ,,,,,,

Pls give me flow of steps to do it 

rgds

So, all from above discussion what i understand is...

If i reuired faster pickup than i need more power, so while purchasing a car i need to look at power factor.

New my question is Disel car has same pickup like petrol car....??

Exp. If i want to compare pickup between HONDA CITY (Petrol) v/s Volkswagen Vento (Diesel)....??

OR

Compare pickup between Volkswagen Vento (Petrol) v/s Vento (Diesel)....??

which one give me more pickup...??

By pick-up, if you mean initial acceleration then between the two ventos the petrol version will be faster for the same total car weight (car's own weight including engine's plus passengers and effects). However all else being the same the diesel vento will be heavier than the petrol version because diesel engine is generally heavier than petrol one. That said, if you want better pulling power at low speed then diesel wins.

Thanks rohit,

Plz tell me how to calculate weight to power ratio...??

Also regarding my question pickup.....

i have taken test drive for Dzire petrol & Diesel. But i feel that diesel has more pickup than the petrol one. May be the condition of Demo Dzire is not good that's why i feel like this.