Reviews & Road Tests
Driven: Audi A4 1.8T with Multitronic
By by: George Achorn, photos by author
Nov 16, 2001, 14:28

While some may scoff at a front-wheel-drive equipped Audi, claiming it as less significant than its quattro brethren, the new Audi A4 FrontTrak (Audi speak for front-wheel-drive) equipped with Multitronic could be one of the most significant cars to roll out of Ingolstadt in some time.

Why you ask? Besides the fact that this is a totally new A4, the first car to be based on the B6 platform, this front-wheel-drive A4 happens to be fitted with one of the first production chain-driven continuously variable transmissions (a.k.a. CVT) that Audi has dubbed Multitronic.

Multitronic: A New Approach to CVT

While traditional geared transmissions usually have a number of set gear ratios, Audi's new CVT uses a chain drawn between two variators (consider them split pulleys where the two sides can be moved closer together or further apart) to create an infinite number of gear ratios.

CVTs have been traditionally used on smaller engines largely due to limitations of the more common belt driven systems. By using a chain, Audi has achieved application of a CVT for higher torque levels. The Multitronic is rated for 230 lb ft. of torque, making it even useable with the new 3.0-liter V6.

One of the more ingenious facets of Audi's CVT implementation is their choice to include preprogrammed ratios in the Multitronic system. By doing this, they allow for a manual shift experience much like a traditional Tiptronic, though with 6 ratios rather than the 5 ratios found in Tiptronic-equipped models. To the common user, when in manual mode, this is a 6-speed automatic or at least it sure acts like one.

Another key element of the Multitronic system is its use of an electronically controlled multi-plate wet clutch rather than a torque converter. The flexibility of the Multitronic CVT allows Audi to drop the heavier torque converter and thus save considerable weight, yet the clutch still provides the "creep effect" at idle much like an automatic transmission.

A magnesium housing is also used for the Multitronic unit in a further effort to keep weight down. All things considered, Multitronic is a relative featherweight, coming in 33 pounds (15 kilograms) lighter than the equivalent automatic transmission.

The All-New A4

The new A4 is a striking addition to the Audi lineup. Its new design borrows heavily from the revolutionary A6; a calculatedly conservative redesign of a highly successful car positioned in an very competitive market. While the design breaks little new ground, it does make use of some handsome Audi design cues such as the large upper and lower front grills found on the A6 4.2 and the jewel headlights that bear more than a passing resemblance to those on the TT.

The new platform boasts some marked improvements. The frame of the new car is 45% stiffer than its predecessor, while the base suspension is roughly the same as the previous car's Sport Package setup. Rear seat room is also improved; perhaps the most apparent shortcoming of the previous car.



At The Wheel

Several things are immediately obvious when you take to the road in a new A4, though the most obvious is the stiffness of the car. The solidity is striking, making it feel like other cars produced by the German "Big 3", though from size classes above the one in which the A4 resides.

The downside to this is of course additional weight. The larger size and increased rigidity, both welcome additions, do take their toll on the mass that the car has to pull around and the difference this has on acceleration is slightly evident on the 1.8T, which carries over unchanged from the older model.

Acceleration in automatic mode is quite different than what drivers are familiar with. There is no perceived change of gears, which seems just slightly unnatural to the casual passenger who might take notice. One gets quite accustomed to it though, especially when they consider that the car is constantly using its most economic ratio.

Use of the unique chain design also eliminates the traditional rubber-banding tendencies of previous CVTs from other manufacturers. In the past and even currently on some other current CVTs, there is a delay in acceleration as the band stretches, whereas Audi's unique chain eliminates this side effect.

Another pleasant aspect of Audi's CVT is its use of torque braking. Ingolstadt has set the car's computer up to apply torque braking when the car's brake system is put into use. This safety feature helps the driver to maintain control under hard braking in inclement weather and produces an effect that acts in tandem with the ABS system in an effort to keep wheels from locking up.

Switch the car into manual mode and things get very interesting. Like the Tiptronic, the new car continues use of the gear indicator in the gauge cluster, though it now depicts six gears rather than five.

Shifting between the preprogrammed ratios is virtually immediate. Where the Tiptronic system would take what felt like several seconds to shift under hard driving, the Multitronic shifts as soon as you command it to.

Even more interesting is that these gears are preprogrammed. It's fairly safe to assume that either Audi or the companies who earn their living tuning the cars from Ingolstadt for higher performance levels will eventually be able to tweak the gear ratios of the cars. It's feasible to conclude that at some point, even owners will be able to adjust gear ratios from their car's trip computer.

Multitronic will initially only be available on FrontTrak cars. A4s equipped with quattro and Multitronic are expected sometime next year, replacing current Tiptronic offerings. And replace it should. While Tiptronic is a genuinely good transmission, it cannot match the performance levels of Multitronic, which readily outperforms it in both acceleration and fuel economy. In fact, tests in Europe where Multitronic has been on the market for several months show that Multitronic cars are even slightly faster and more frugal than equivalent manual transmission cars.



Summary

If it sounds like we're raving then you are hearing correctly. With the exception of its previously mentioned torque limitations, the new Multitronic system offers superior performance levels while also retaining the option of an automatic option for those who choose to not choose their gears. While we're not sure we're ready to give up on shifting our own gears, as there is something very satisfying about that, the fact remains that Multitronic is so good, this author would very seriously consider replacing his manual transmission with a new Multitronic. Now about adding quattro·?

For more photographs of this story, click on the link to our galleries at the left.

© Copyright 2004 by YourSITE.com