Audi continues to offer its S4 in sedan, wagon (Avant) and convertible (Cabriolet) body styles for 2008. Bluetooth-based cell phone connectivity and Sirius Satellite Radio are now standard, and RS 4-like 18-inch alloy wheels are available. Competitors include the Cadillac CTS-V and Lexus IS-F.

Quattro all-wheel drive is standard on all S4 models. A Torsen torque-sensing center differential helps send power to the wheels with the most traction. The extensive use of aluminum in the suspension results in low unsprung mass.

All Audi S4 models come with a 4.2-liter V8 engine that generates 340 hp. This allows the S4 to jump to 60 mph in just 5.3 seconds with the standard six-speed manual transmission. There is also a six-speed Tiptronic automatic transmission that allows manual gear selection optional. The S4 comes with Audi’s quattro all-wheel-drive system and BBS 14-spoke, 18-inch alloy wheels with high-performance tires.

Ripping a page out of the Mercedes-Benz playbook, Audi is starting to give each of its models a massaged performance treatment that replaces the standard “A” prefix for each model with a much sexier “S” much the same way its home-country rival has been adding the AMG suffix to everything in its lineup. The Audi S5 that debuted at the 2007 New York Auto Show is the tuned and tweaked version of the stunning A5 coupe that hits U.S. shores this summer, equipped with a powerful V8 engine, sport tuned suspension, upgraded brakes, and other modifications designed to optimize performance. The Audi S5 goes on sale in June at about the same time that the A5 arrives in showrooms.

Inside, front occupants are treated to a comfortable and functional cockpit. Leather seating is standard, and interior trim, lighting and controls are all of high quality. Most of the A4′s features come standard on the S4, including dual-zone automatic climate control and HID headlights. Although the rear seat is fine for small children, adults seated back there will likely complain about a shortage of legroom. The Avant sport wagon provides up to 61 cubic feet of cargo space with the rear seats folded.

Buyers interested in a used Audi S4 should know that the current model dates back to 2004. This is the third-generation car. Previous to this model, there was the second-generation S4 available from the 2000 to 2002 model years and the first generation available from 1992 to 1994.

Audi’s 4.2-liter V-8, which is also used in the automaker’s larger models, was modified to fit into the S4′s compact engine compartment. Developing 340 horsepower at 7,000 rpm, the V-8 produces 302 pounds-feet of torque at 3,500 rpm. Audi says the S4 can accelerate from zero to 60 mph in 5.3 seconds when equipped with the six-speed manual gearbox. A specially tuned exhaust system is installed. A six-speed automatic transmission that features a manual-shift provision is available.

2008 Audi S4 Models:

2008 Audi S4 Sport Sedan 
2008 Audi S4 Avant 
2008 Audi S4 Sport Sedan with Tiptronic 
2008 Audi S4 Avant with Tiptronic 
2008 Audi S4 Cabriolet 
2008 Audi S4 Cabriolet with Tiptronic

Certain design aspects of the R8 might bring to mind a Porsche, a Corvette or the late Acura NSX, but because the R8 carries a 4.2-liter V8 in its midsection, sends 420 hp to all four wheels, offers two transmissions and wraps it all in an aluminum space frame, this Audi clearly has its own attitude. The only car coming close to that description wears the name Lamborghini Gallardo — no surprise, as that midengine exotic provided the basic blueprints for this one. Audi’s $70-grand-lower price tag ensures the competition will be minimal, as does the R8′s two fewer cylinders and 100 fewer horsepower.

Yet the R8 is undoubtedly fast. Sixty miles per hour comes up in 4.4 seconds, a quoted top speed of 187 mph arrives not much later, and tire grip approaches a full g — all par for this potent class. Among the bigger differences: the R8 lets its driver exploit that speed through a six-speed manual or “R tronic” transmission (Audi’s newest take on the clutchless manual); Audi’s Quattro all-wheel drive allows hard driving with an extra degree of confidence; and perhaps above all, the R8 incorporates Audi’s usual concessions to comfort rather than raw performance. Consider its advanced, ride-friendly electromagnetic shock absorbers, for instance.

It’s one of those amazing roads you can’t help but come back to: a rhythmic mix of fast and slow sections, first wide open and then tree-lined on both sides, mostly smooth but dotted with patchwork surfaces here and there, a mild yet steady climb from the bottom of the valley to a high plateau of open fields and rolling pastures. Only five miles long, this challenging stretch of tarmac tells you more about a car than two weeks of bumper-to-bumper commuting. That’s why we–the gunmetal gray preproduction Audi R8, chief project leader Dirk Isgen, a couple of minders from the factory, the photographer, and me–are here. Unfortunately, I won’t be driving. What, you think there’s no way of finding out how a car performs from the passenger seat? Well, let’s give it a try.

Down in the village, Isgen executes a U-turn, and we speed up the magic mountain for the first time. Even though he changes gears at a relaxed 6000 rpm–some 2250 rpm shy of the redline–the two-seater feels light-footed, inspired, and very, very quick. Fourth gear seems to be fine for the quicker corners, and third is all it takes for the panoramic 90-degree stuff. No drama, no exultation, no pulling or pushing, absolutely no indication of zooming in on the limit, let alone overstepping it. Quite the contrary: the R8 corners with the precision of a pair of micrometers.

The production R8, which we were recently allowed to drive, looks surprisingly similar to the Le Mans concept car, first shown at the Frankfurt Motor Show in 2003. Even the extremely low front end, contrasting side panel beside the engine compartment, and LED driving lights and taillights been carried over into the production car (all-LED headlamps – claimed to be the first in any production vehicle – will be an option starting late this year). Also carried over from the show car is the rear glass that allows a view down, not into the luggage area but into the engine compartment, where the 420-hp, 4.2-liter direct-injection V-8 is presented like a museum piece.

2008 Audi R8 Models:

2008 Audi R8 Coupe quattro 
2008 Audi R8 Coupe quattro with Auto R tronic