Originally Posted by Spicywolff

I thought I saw a FCP euro video that the C could be optioned with air suspension

Originally Posted by superswiss

Quattro means 4 in Italian . If you meant what my take on quattro is (lower case spelling), then first off quattro is a brand and not a technology. Much like 4Matic. Not all quattro is the same. The entry level models such as the various variants of the A3 for example use a rebranded Haldex system. Same system is found in the VW 4Motion products. Haldex is a transverse system with a front transaxle that permanently drives the front wheels, so fundamentally these are FWD cars. Power/torque can be sent to the rear wheels via a multiplate clutch as needed, so it's technically not AWD, but FWD with partially engaged rear wheels.

Similarly a few years ago, Audi came out with quattro ultra for the A4 platform. It's found in the 2.0 liter and below models as quattro ultra can't handle all that much torque. It was designed to reduce the fuel economy penalty that inevitably comes with AWD. Like with Haldex, the front wheels are permanently driven and via a multiplate clutch power/torque is sent to the rear wheels as needed. However, in addition the driveshaft can also be decoupled from the rear differential via a dog clutch, so it comes to a complete standstill in FWD mode instead of kept in rotation by the momentum of the rear wheels. This reduces loss in the drivetrain and consequently a better fuel efficiently. As opposed to the Haldex system, quattro ultra also uses predictive algorithms to determine ahead of time when AWD is needed, so that it is engaged about 200-300 ms before it's needed. Various inputs are factored in such as drive mode, acceleration, yaw etc. It even determines if the driver is a dynamic driver or a casual driver and in the former cases it engages AWD more often.

The quattro system that most people think of when talking about quattro is the system in the A4 and above. This is often referred to as true quattro. The R8 has a similar system as 4Matic+, where the rear wheels are permanently driven and the front wheels are engaged via a multiplate clutch as needed. Essentially a reverse Haldex system. True quattro famously used a Torsen center differential. Like in a limited slip differential, it can lock based on rotational speed differences between the rear and the front and force torque to the axle with the most traction. This is all completely mechanical and therefore very fast acting. 4Matic+ and other systems control things electronically, so there is always a bit of a delay before the power/torque is redirected when a loss of traction occurs.

Nowadays true quattro uses self-locking center differentials with a clutch pack. It's still fully mechanical. The forces that occur in the center differential when the front and rear axle rotate at different speeds causes the clutch pack to engage and start locking the differential at various ratios depending on the traction differences. Again, this is how more modern LSDs work, but different from how the electronic locking differential in the 63 models works. Which like 4Matic+ is electronically controlled and locks at various ratios based on an algorithm and the inputs from several sensors. But the e-diff is actually more effective and faster acting than a mechanical LSD, because it can proactively lock the rear differential during launch control for example and also based on steering input during cornering. A mechanical LSD requires loss of traction before it starts locking, but the e-diff can start locking before loss of traction even occurs, because it knows when the driver is starting to steer into a corner. Basically quattro ultra as described above is attempting a similar thing and tries to predict based on driver input if it needs to engage AWD before loss of traction occurs.

Having said all that, quattro at least true quattro is more utilitarian and has better all-weather traction, because it's fully mechanical. 4Matic+ and other electronic systems often struggle in low grip environments as the electronic controls try to figure out where to send the power. The below video is a good comparison that shows how quattro is much more confident in the snow, whereas the Merc and BMW are kinda all over the place and experience much more wheel spin. 4Matic+ and similar systems are more performance oriented, because they primarily drive the rear wheels and are mostly RWD in normal traction situations. In the AMG models such as the E63, the front wheels can even be completely decoupled via the drift mode for a true RWD drifting experience. This is something that quattro simply can't do.

https://youtu.be/NRpDBzFFI1g

Originally Posted by W205C43PFL

I am however confused about audi's decision to use ultra, as the word ultra isn't meant to be seen as superior, or at least it sounds that way?

As from what I understood with what you said, the "Ultra" refers to ultra efficiency as for the few models that use it, audi believes buyers are looking for reduced emissions and better fuel consumption (through coasting in FWD when no slip is detected and AWD isn't needed). They keep the full time, rear bias balanced AWD ("real Quattro") for the S and RS model cars.

So in the case that people think they have the superior version "ultra" but is actually is their least capable system?

So we can say it is misleading then? If it wasn't marketing I assume this system would had been called quattro efficient or quattro lite?

Originally Posted by superswiss

Yes, Audi uses the Ultra terminology for all technologies that reduces CO2 emissions and fuel consumption.

Originally Posted by W205C43PFL

I see so ya does sound misleading for those that interprets it the way I do, you would think ultra means superior...

Originally Posted by superswiss

Well depends on superior in what area. The definition of ultra is "going beyond what is usual or ordinary". They are going beyond in the area of emissions and fuel consumption with the ultra models.

Originally Posted by superswiss

Yeah, you do have to understand that AWD isn't all that great overall. Its usability is very limited. Mostly off the line to about 30 mph. After that AWD is actually inferior, because of the added weight and increasd drivetrain losses. Some organization once did a study and came to the conclusion that AWD only has benefits about 1% of the time, while 99% of time it's a disadvantage. Drivetrain losses of AWD are quite high compared to FWD and RWD. Below are the typical ranges.

Europeans are more sensitive to this. FWD models are actually more popular, because for the most part they are sufficient in the winter and are more efficient overall than AWD. Most people really don't need AWD. It's one of these perception problems.

■FWD: 10-15% loss;
■RWD: 10-18% loss;
■AWD: 17-25% loss.