Torque Curve/Butt Dyno X3 M40i VS B9 S4

[Manbeardogcat]

Hi lads,

Was wondering if anyone with more technical knowledge than me could help me understand why something would feel faster even though it isn't. I understand diesels feel faster as they have loads more torque and from far lower. But the 2 cars I'm referring to today have identical torque numbers.

We just took delivery of a X3 M40i (285kw version) and on the way home with myself driving the S4 and wife in the X3 we went from 10mph to around 70mph, the X3 was marginally quicker.

However when I drive the X3 it feels a little slower, the S4 feels like it has quite a bit more initial shove to it.

Looking at the Dyno charts the S4's EA839 motor reaches peak torque at 1370rpm, the B58TU in the X3 reaches peak torque at 1900rpm, will the S4 reaching peak torque 500-600rpm sooner really play such a role in making the car feel faster? As their torque is identical, but the X3 M40i has 25kw more.

For those who have driven SUVs before (this is our first), does weight also play a factor in how fast a car "feels"?

Thanks for any inputs

[georgeyboy12345]

Manbeardogcat said:

will the S4 reaching peak torque 500-600rpm sooner really play such a role in making the car feel faster?

Yes, but it’s mainly because the S4 is over 200 kg lighter

[rottenegg]

Regarding the 10 - 70mph thing, I'd say the ZF8 in the X3 plays a part. It's a good disguiser of weight, and there's no cut in power between shifts. Engine torque is different to torque at the wheels via gearing.

Edited by rottenegg on Saturday 21st October 01:25