Quattro Experts. Is This True?
 

Found this on a Lexus forum:

"Actually, if you did not know.... Quattro is just Audi's marketing name for the AWD system that is employing TORSEN differencial front and rear. With full-time 4x4, often 50/50 spit (traditionally), and recently more like 40/60 split (such as my RS4 had).

But wait, Toyota/Lexus has been using this setup for ages. Same time frame as Audi (remember Toyota Celica of the first Audi Quattro vintage? Both competed against each other in WRC?). Ever since Toyota used full TORSEN 50/50 on most of its vehicles. The LS600h has this setup as an example. My LX470 is using this exact setup. I probably should put "quattro" on it then Only recently Toyota started to cheapen out the transmission, on the later generation RX330/350 (the first one was full TORSEN) etc. Which is a shame.

Then it gets even more funny - the newer lower end Audi vehicles these days started to get the HALDEX diffs, such as the current A4 and A3. Still called "quattro" in Audi speak... and this is the company that until recently was saying the nothing compares with quattro which can be nothing less than dual TORSEN 50/50 setup. This is the real LOL."

Nope, not even close on Toyota's especially
 

Yes, Audi is Torsen for all but the transverse motors in the old Golf platform grouping--A3's, TT's, etc. Longitudinal ones from the A4 up, and all the SUV flavors are conventional quattro as you think of it. Moved from 50:50 split to 60:40 on many now, and also now integrating brake intervention a la Acura SH-AWD for yet more handling on the newest designs.

Putting aside the "truck type" Toyota 4WD's with full transfer cases, their systems are typically just adapted FWD with a take off to the rear and clutch pack. Most of the time its 95-100% to the front, and rear only as needed. That's the Sienna platform, which is then the RX platform, Highlander, etc. I owned a Sienna AWD so know the system well. It works, but it's basic. And lose traction on more than one wheel, especially on the same side or diagonally opposite and it's a nailbiter if you get stuck. Audi handles that easily. RX Hybrids in AWD apparently "cheat" by using the electric motors to drive the rear; does cut down on weight anyway. Having owned the Sienna, the older Chrysler T&C system from the mid 90's that I also owned was actually a more robust design, also an AWD take off of a transverse FWD; built by Steyr in Austria for them. Finally on the Toyotas I also like when the underdesigned rear diff positioning mount gave way, and left like literally a foot of play in the parking brake. Apparently a routine failure on them, at over $200 just for the part to deal with the faulty bushing, let alone the safety issue on grades, especially parking uphill and opening the rear tailgate when stopping.

The rest of the post is all over the map on truck type systems, high end non sellers like the LS600, so awfully diverse to tackle all. Net though, its oversimplified, sweeping and misleading relative to their volume systems.

Not really. Quattro employs Torsen only as a middle differential. Front and rear are just simple opened differentials, except on some sport models where at rear is classic limited slip differential. It also employs EPS, or better say brakes, to stop spinning wheel. Basically same as Mercedes and BMW. Classic 4wd with all limited slip differentials would increase consumption and hurt on road performance.

Don't now and don't care about Toyota :).

Acura's Super Handling is over complicated and wrong way to prevent understeer.

Sure they use Torsen centre differentials in most models and call it Quattro, I don't see that as any different to using ZF Autobox and saying Tiptronic transmission.

The Quattro principal goes much further than just the Torsen centre diff, Quattro refers to the whole AWD system, including torque vectoring rear diffs on the latest sporty models.

Actually that new system does not have Torsen differential. Rear differential was designed with the same idea as Acura's SH drive, just more elegant. Idea tested by Porsche 20+ years ago and never used again. It is rather granny than sports concept.