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

crispy_chris

I'm currently looking to get a new car, but I'm struggling to work out what engines will 'feel' like in the real world. Obviously in this day and age you're bombarded with stats, but I'm not entirely sure what they really mean.

Currently I have a 2.0L Diesel Vauxhall Insignia with the following numbers
- 140 BHP
- 258 lb/ft torque
- 10.5s 0-60 time

Picking a similarly sized car at random (1.5L Petrol BMW 3 Series) with the following numbers
- 134 BHP
- 162 lb/ft torque
- 8.9s 0-60 time

Or a smaller car (1.5L Petrol Audi A3) has:
- 148 BHP
- 236 lb/ft torque
- 8.5s 0.60 time

So, perhaps naively I would imagine that the Audi would be the more powerful car at accelerating due to the lower 0-60 time. However in my own head previously I'd though torque represented accelerating power, which would make the Vauxhall look to be the more powerful accelerating car. Then looking at the BMW which has a pretty similar 0-60 time to the Audi, but has a far smaller amount of torque.

I'm just trying to work out which car would be the fastest feeling car at accelerating in the real world, but colour me confused! :huh:

Car_54

0 to 60 is not the most helpful measure in real life: sone reviews give in-gear acceleration times.

BHP on its own is pretty meaningless: you need to know the car's mass and hence its power/mass ratio.

The BMW is less powerful, and has less torque than the Vauxhall, yet has better acceleration. That suggests it's much lighter. Or that one or both makers is telling porkies. Or all of the above.

facade

The torque varies with engine speed, so that single figure could be when the engine has got to its maximum rpm.
You want the shortest 0-60 time for the best acceleration from the lights.

Just get a Dodge Challenger SRT Demon with the 840HP pack. $86,000 (I'd go for granite grey)

Joey drove one in Top Gear, it sounds fantastic, like being in the first Mad Max film

crispy_chris

I just wanted to be sure I didn't get a car that felt less powerful than the one I'm using now. I'm quite happy with the Vauxhall's performance overall, when the turbo kicks in it feels like it moves a reasonable amount. Of course there's no obvious way to tell though, why would there be :undecided

Not sure I'm quite ready to move to the Demon though

facade

crispy_chris wrote: »

Not sure I'm quite ready to move to the Demon though

Top of my list when I become a lottery millionaire

1.8g acceleration off the line- lifts the front wheels off the floor
0-60 in 2.3 seconds
0-100 in 5.1 seconds

What's not to like?

n217970

When do you want the acceleration? For overtaking or for beating boy racers off the line? One of my diesels (0-60 in 7.6 seconds) will keep up with and may actually beat my brothers petrol (0-60 in 6.3 seconds) in the 40-70 range. But 0-30 he has me comfortably beaten.

He has 45 more Bhp, I have 75 more NM of torque. He also benefits from 227 less kgs.

This is before we even get into gearing of course....

redux

facade wrote: »

You want the shortest 0-60 time for the best acceleration from the lights.

Far more relevant in the real world are +20 mph or so accelerations from alresdy moving, changing down one or two gears, or indeed not at all.

Someone swapping from a diesel, where the maximum torque is available at 1500 to 2000 rpm, and going from 40 to 60 or 50 to 70 mph is pretty relaxed, will probably find a petrol car feels like it has less urge, until they revert to the old habit of dropping down more gears.

crispy_chris

n217970 wrote: »

When do you want the acceleration? For overtaking or for beating boy racers off the line? One of my diesels (0-60 in 7.6 seconds) will keep up with and may actually beat my brothers petrol (0-60 in 6.3 seconds) in the 40-70 range. But 0-30 he has me comfortably beaten.

He has 45 more Bhp, I have 75 more NM of torque. He also benefits from 227 less kgs.

This is before we even get into gearing of course....

Yeah it's actually more from the 20mph+ range I'm looking at. I'm not a boy racer, I just like the ability to get some grunt on demand when overtaking or what-not.

redux wrote: »

Far more relevant in the real world are +20 mph or so accelerations from alresdy moving, changing down one or two gears, or indeed not at all.

Someone swapping from a diesel, where the maximum torque is available at 1500 to 2000 rpm, and going from 40 to 60 or 50 to 70 mph is pretty relaxed, will probably find a petrol car feels like it has less urge, until they revert to the old habit of dropping down more gears.

If it makes any difference I'll probably be taking an auto this time around, so it'll drop down whatever gears it feels it needs to I suppose!

wgl2014

I wouldn't get too hung up on the numbers.
Have a test drive and see what the car feels like to drive.

crispy_chris

wgl2014 wrote: »

I wouldn't get too hung up on the numbers.
Have a test drive and see what the car feels like to drive.

Absolutely, I was just hoping to avoid having to test drive a few different engine variants of the same car by understanding the numbers, but alas it doesn't appear to be that simple!

mchale

crispy_chris wrote: »

I'm just trying to work out which car would be the fastest feeling car at accelerating in the real world, but colour me confused! :huh:

I would look at the 30-70 times.