tubi

I don't get it. Why the B8 quattro system is superior to other AWD cars even if they use the same haldex system?<ul><li><a href="http://en.wikipedia.org/wiki/Haldex">http://en.wikipedia.org/wiki/Haldex</a</li></ul>

Q5Steve

Take another look at your link. Only the A3 and TT use a haldex system. It is clutch based and so theoretically at least no physically "solid" conection between power in and power out. It is a type of torque transferrer if you will.

All other current Audi Quattro systems are based on a Torsen centre differential. I am sure someone else here can explain - to us that have no clue - exactly how that works but I know it has no clutch and therefore keeps a constant mechanical connection between power in and power out. It is a limited slip diff.

This is my understanding of it and word is the latter is the gold standard.

Can someone else please embellish the details.

tubi

B8 uses Haldex not Torsen

SoSuMi

Wanna bet a bottle of single malt on that?

http://www.autoblog.com/2008/04/06/first-drive-2008-audi-a4-on-the-autobahn-and-in-ibiza/3

The A4 has always used the Torsen center diff.

Bob58

If you reverse the names Haldex and Torsen your statement will be 100% correct.

Q5Steve

Because in the link that you posted yourself it says, and I quote

"unlike longitudinal engine models (Audi A4, A6, A8, previous-Volkswagen Passat) which use a Torsen centre differential."

Need you say more?

markcincinnati

. . .the A4 does NOT use Haldex. It DOES indeed use the torque sensing system called TorSen.

A key, if not THE key differentiator pertaining to the TorSen Quattro application is that the torque transfer is "instantaneous." It is NOT reactionary -- TorSen as compared to Haldex, "binds (transfers torque) in real time." Haldex is quick, don't think that it is in some way a bad system, i.e.

TorSen, however is better in at least the characteristic that we might call reaction time. Haldex on the one hand "waits" for slip to react. TorSen acts in real time.

Couple the current Torsen system with rear wheel drive torque bias, the ability now, to have torque vectoring (side to side torque transfer) and an overall design that makes some of the current and the future Audi models far far less nose heavy and you have the "best" AWD that can be had without graduating to expense that would make these cars made of unobtanium.

The downside of the Torsen Quattro system? Weight (it does weigh more than other AWD systems for instance, Haldex) and expense -- it is not as inexpensive as other AWD systems.

The plusses outwigh the minuses for most folks, even those who actually write this stuff for a living.

When reading about the various applications, there is merit in reading to the end -- you would have come across the fact that Haldex is used in the A3 based Audis.

The A4 remains a "true" quattro.

GDawgA4

""Haldex" refers to the aforementioned differential system -- its most prominent use is in all transverse engine 4x4 models of the Volkswagen Group: (Audi A3 and TT, and Volkswagen Golf )"

"unlike longitudinal engine models (Audi A4, A6, A8, previous-Volkswagen Passat) which use a Torsen centre differential"

Still think the B8 is Haldex?

justhacking

Are you having trouble reading today? It's Torsen.

antiSUV

"Now standard across the A4 line on quattro equipped vehicles is the asymmetrical 40:60 split Torsen center differential."<ul><li><a href="https://www.audiworld.com/news/07/frankfurt-show-review/content.shtml">Full report</a></li></ul>