Road test: 2002 Audi A6


Audi’s A6 has always been a great car in search of an engine. Possessed of a great face, superlative roadholding and a comfortable, expansive interior, it has been consistently let down by a base engine lacking in the torque that North Americans demand from their performance luxury cars.

Said engine has been, until now, a 2.8-litre V-6. It has the de-rigueur double overhead cams that performance engines are supposed to have and even one more valve (for a total of five) in each cylinder than normal to maximize efficiency. Nonetheless, its maximum horsepower of 200 has always been near the tail end of near-luxury class and its low-end torque even more suspect.

Audi recently added additional engines to the A6’s coterie, namely the turbocharged, 250-hp 2.7T and the 300 horsepower 4.2-litre V-8 (both of which continue largely unchanged). Both generously solved the A6’s power deficit (albeit for a serious wad of cash), but also served to amplify the torque deficit of the base engine.

The German company obviously got the message because for 2002 the base engine has herded an extra 20 ponies thanks to an increase in displacement to 3.0 litres. And while maximum torque is only increased 14 pound-feet to 221, it occurs at a low 3,200 rpm.

As well, Audi makes much of the fact that the 3.0-litre version’s longer stroke adds dramatically to its low-end torque. It’s a worthwhile increase that puts the A6’s output into the heart of the European near-luxury segment and lets the company claim that the new car is about a second faster to 100 km/h than the old.

In actual testing, though, the A6 still doesn’t feel quite as fast as its competition – at least in its quattro, five-speed automatic-transmission guise.

Audi claims an 8.7-second acceleration time for the automatic-equipped quattro – improved, but still not stellar performance. The 3.0-litre is a step forward, however, since the A6 now feels adequate whereas the previous version was definitely anemic. Where trying to accelerate, the previous 2.8 version required much downshifting and a flurry of rpm to get anything remotely resembling meaningful acceleration; the tourqier 3.0 is much more willing to move the A6 without so much drama.

Adding to its horsepower advantage is that in completely redesigning the engine, Audi cast the new block in aluminum, saving about 20 kilograms of unwanted weight. While they were at it, the company slipped a balancer shaft into the 3.0-litre version, to better quell any vibration caused by the V-6’s 90-degree vee layout (the more common 60-degree V-6 is more naturally balanced and generally doesn’t require such an addition).

As worthwhile as the new engine is to the A6’s performance, it pales in comparison to its new multitronic transmission. Like the new Mini’s powertrain, the multitronic is one of the new continuously variable transmissions (CVT) that promise to render the current crops of automatic obsolete. Like the BMW-produced Mini (and almost all snowmobiles), the Audi’s transmission uses a set of pulleys and a belt (Audi’s system actually uses a linked chain) to offer an almost infinite number of ratios as it completely eliminates the internal gears.

The Audi’s system, however, is more sophisticated than BMW’s. For one thing, the multitronic’s function has been tailored for easy acceptance by North American drivers without compromising the CVT’s advances in efficiency. When accelerating, traditional CVTs immediately increase rpm to a steady point (about 5,000 rpm in the Mini’s case) and then increase speed by continuously varying (hence the name) its gear ratios. Because the engine’s rpm is held close to its torque peak, a CVT is actually more efficient than a manual transmission. Indeed, a multitronic A6 is 0.1 seconds faster to 100 km/h than the same car equipped with a manual transmission (not available in North America).

The downside is that since the motor is held at a constant rpm, there’s less sensation of acceleration – something, say both Audi and BMW, that has prevented universal acclaim for CVTs among the focus groups that have tested their cars.

Audi gets around the problem by engineering in a few attributes of a traditional automatic. Primary is that, unlike a pure CVT, the multitronic system does increase rpm as speed increases, only there’s no sensation of the gear shifting. Another feature engineered in for consumer acceptance, not for efficiency, is “creep.” Unlike traditional automatics, a CVT will not move forward at idle when you release the brake. Because they were adamant about gaining acceptance in our conservative market, Audi’s engineers actually contrived some creep into its multitronic system so that it would feel more like a normal automatic.

Whatever the compromises it’s made, the multitronic is nothing short of a revolution in transmissions. For one thing, here’s a put-it-in-D (for drive) transmission that actually accelerates better and gets superior fuel economy than its manual counterpart. It even feels more sporty, responding to matting of the throttle with an almost immediate increase in rpm and instantaneous acceleration. And because a CVT can offer a much wider spread of gears than a regular transmission, the multitronic’s top ratio is much taller, revving the engine at only 1,700 at 100 km/h compared with the manual version’s 2,600 rpm.

That’s why the multitronic gets better fuel economy than the manual. It also means the multitronic-equipped A6 feels much smoother and is significantly quieter at cruising speeds.

In fact, the multitronic is superior in virtually every way to the A6’s current automatic. Since there are no gears, there are no harsh shifts and the multitronic is smoother than even the best automatics. It also “kicks down” much more quickly for better acceleration. Most of all, it feels “normal,” which means it’s likely to gain mainstream acceptance. In fact, most Audi owners who opt for the multitronic won’t even know that they’re driving revolutionary technology, so seamless is its performance.

For the foreseeable future, however, it’s only available on the FWD A6. Quattro versions will soldier on with its traditional five-speed tiptronic automatic for at least a couple of years.