Torque, BHP, 0-60 times - real world feel?

IamNotAllowedToUseMyName

The main benefit with the modern torquey diesels is not the high torque but the wide, flat band in which it is delivered.

A petrol engine tends to be peaky - I remember my 1.6 Golf really only delivered interesting acceleration over 4000 revs - it was tuned to be economic, but they also wanted to give performance, so you had to work the engine and gears to get the performance - it was there but needed thought and effort to get it.

On a modern diesel, you have something that delivers torque and power very low down the rev range, 1300-1400 revs is producing large amount of torque on my car, and it can deliver beyond 4000 revs, so something like 80% of its usable revs are giving high torque, whereas a petrol engine may not deliver large amounts of torque until 3000 revs and may drop off after 5000 revs. Combine a torquey diesel with a good auto box and you can get a pretty steady and continuous acceleration 0-70 - you can watch the accelerator follow a steady and rapid climb.

So modern injected turbo-diesels feel good because not only can they deliver strong acceleration, they can sustain it across the rev range, and they make very little fuss and noise doing it.

oscarward

Just for illustration I used to have a twin turbo 3.0d which had 240hp, 0-60 6.5 secs.


I was loaned a 2.0 turbo petrol similar sized saloon when the other car was in service.


This also had 240hp 0-60 6.5 ish .


What I did notice to get the same performance the revs were considerably higher. e.g. 70 was 1800rpm in the diesel or 2400 in the petrol. 100 was 2000 rpm vs 3000 in the petrol.


So to travel in my usual style the revs were much higher which did seem to be more stressful to me. If I had bought one then I may have got used to it but I decided I didn't like the loan car for more reasons than just the engine package.

System

BHP per tonne is what matters from 0-60. Smaller cars lower to the ground feel faster than larger cars. My MX5 has only 160BHP and 0-60 of around 7.8 seconds but you're sat on the floor so 40 feels like 60 and it feels a lot faster whereas in my Mondeo 60 feels like 40.

However we don't spend all our time accelerating from 0-60. 40-70 acceleration time is more important to me as I spend a lot of time overtaking braindead holiday makers on my way to and from work on a single carriageway A road. My Mondeo can out drag a BMW 328i from 40-70 despite being lower down on power and having a slower 0-60.

As IanMSpencer alludes to, where the power is delivered is important. Diesels feel pokier than petrols because they deliver their power from quite low down in the rev range, between 2000-4000 RPM they have a fair amount of grunt. Petrols do it much higher. My MX5 for example feels as flat as a fart below 3500 RPM but when it hits that it is off like a rocket. Most people rarely drive around at 3500/4000-6000RPM during normal daily driving so they rarely use the maximum power their petrol engined car has.

Gloomendoom

Tarambor wrote: »

BHP per tonne is what matters from 0-60.

When my wife was looking for her first brand new car, she worked out the power to weight ratio of all the candidates on her shortlist and bought the one with the biggest number.

Head_The_Ball

Gloomendoom wrote: »

When my wife was looking for her first brand new car, she worked out the power to weight ratio of all the candidates on her shortlist and bought the one with the biggest number.

When my wife was looking for a new car I discussed with her all the issues such as manual versus automatic, petrol versus diesel, performance versus fuel economy, bhp, torque etc.

In the end she chose a red one because it matched her favourite lipstick.

gregpot2000

Simply put. Torque is that pinned back in your seat feeling you get when accelerating hard, more Torque generally means it's funner to drive if you're into all that