First Drive: 2013 Audi S8

It's a good bet that the average Audi A8/BMW 7 Series/Mercedes S-Class buyer doesn't care much about dynamics beyond being able to merge ahead of freeway traffic while checking stock prices on their smartphones, or whatever the rich do while commuting. For the rest of us enthusiasts who dream of coming up with the kind of sports-celebrity scratch for a car that can carry the family in comfort while carving up on-ramps, there is the S8. For its first two generations, the S8 was an executive touring car. This one has a different feel. Chassis tuning is more subtle in part because the ordinary A8, with its sport and individual comfort suspension settings, is already pretty competent, and stiffer tuning can only go so far before this big sporting luxury car gets too harsh. Hence, this new Audi S8, which launches next spring in Europe and in late summer or early fall of 2012 in North America, is all about the engine.

Because it can get such great power and torque numbers, Audi put its efforts into making the V8T (as the badging on the S8's front fenders indicates) as efficient as possible. First, Audi engineers placed the exhaust manifold and turbo intercooler within the 90 degrees of the V for quicker and more efficient engine warm-up. More importantly, the direct injection engine has a cylinder cutoff system with a sleeve that kicks in a zero-lift cam to cut cylinders two, three, five, and eight at light loads. The twin-turbo V-8 can run on just four cylinders at engine speeds up to 3600 rpm and at speeds up to 112 miles per hour. The car also comes with a start/stop system in Europe that the company says will eventually make it to the U.S., though not at launch.

The noise, vibration, and harshness characteristics of cylinder shut-off and stop/start understandably concerned Audi, so engineers developed two big technological breakthroughs to mitigate the noise and the secondary vibrations that make their way into the steering wheel and throttle pedal. Two active engine mounts, designed to be much like stereo speakers, use fluid to actuate a permanent magnet that moves a diaphragm and cancels vibration from the shutoff with counter-vibrations of their own. The Audi S8 is in the running to be named the quietest, smoothest car extant. DTR VMS developed (and manufactures) these ingenious active engine mounts for Audi. It's a South Korean company that bought British supplier Avon Automotive, so don't be surprised for these to show up in a future Hyundai Genesis V-8.

One other tasty bit of high tech are the S8's optional ceramic front brakes, which shave 11 pounds off the weight of each front wheel. Audi hasn't decided whether to offer ceramics on U.S. imports, partly because the option could approach the base price of a VW Jetta and partly because ceramic brakes are not linear like steel brakes. A test-drive proved this. There's a lot of play and mush at the top of the pedal, where you expect the binders to effectively shave off speed. Then, when you find yourself stabbing the pedal further to get some results, the brakes really grab. Will American Audi customers put up with that?

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