Zigaroo

apoelistas

My Opinion: They are both similar with the following difference.
Haldex rear differential is open differential with EDL (electronic differential lock).
Quattro Ultra rear differential locks rear wheels mechanically. E.g. when slip is detected on one rear wheel that wheel is locked by the rear differential for transferring torque to the wheel with good traction. In comparison with previous technology or Haldex the ABS/ESP simulate the lock by braking the slipping wheel.

Second would be active torque vectoring, I think that Quattro Ultra has this support. In comparison Haldex supports the brake type torque vectoring.

1. S-tronic with crown differential Q5s I believe support the brake type torque vectoring (Europe 2013-2016), Quattro
2. S-tronic with torsen differential Q5s support EDL. (2009-2012 Europe), Quattro
3. ZF with torsen differential Q5s support EDL (2010-2016 USA etc), Quattro

SYMAWD

quattro ultra is not haldex.

gk1

With the addition of more cameras and self driving I image the ultra system will allow for more predictive engagement of the AWD (like the new A8 active suspension) and the minuscule fuel economy advantage is only really a benefit to the manufactures CAFE numbers.

Also with it being more electronic it could allow for better integration into a "quattro" single electric motor e-tron model in the future.

MurrayA4

Perhaps I'm naive but somehow I'm comfortable with believing that if Audi sticks a Quattro badge on something it's likely to be a pretty good AWD system.Maybe I'm getting old and my opinions are no longer valid ? Subarus come a close second and then there's all the rest.I've never driven a transverse engined Audi - Haldex,eg.Q3 so I can't speak from experience, but it's probably pretty decent.I've driven the Dodge (Charger) Awd which is rear biased and it's actually pretty good and fun but that's getting completely off topic.

Zigaroo