1998 Audi A4 2.8 Tested: The More Valves, the Merrier

Five-valve technology breathes added life into a wonderful sporty sedan.

From the September 1997 issue of Car and Driver.

During our first drive of this new five-valve Audi A4 2.8, we noticed that the only cars able to force us out of the blazing left lane of the autobahn near Audi headquarters in Ingolstadt, Germany, were the bad boys: Mer­cedes S-class and BMW 7-series sedans. We took this as a good sign.

Since its introduction in 1995, the A4 has been near the top of our "Cars We Would Recommend to a Friend" list. Its refinement level is up there with big German sedans costing twice as much, and it has earned a place on our Ten Best list for 1996 and 1997. The only big-time bad experience we have encountered with an A4 happened with our long-term 1996 model (C/D, June 1997), which required a transmission transplant at 30,282 miles.

The only other thing we didn't like about the previous A4 and other Audis in general was the lack of low-end get-up­-and-go. Last year, Audi introduced a new turbocharged 1.8-liter four-cylinder engine with a free-breathing 20-valve cylinder head. That engine produces tremendous low-end grunt for its diminutive size.

Now, Audi has applied this five-valve technology to the 2.8-liter V-6 (formerly a 12-valve engine), but instead of turbo­charging, the six gets variable intake-valve timing working in concert with a variable-resonance intake system. Power has been increased from 172 to 190 horsepower at 6000 rpm, and torque is up from 184 to 207 pound-feet.

Uschi Weps, Audi's manager for four­- and six-cylinder engine applications, says that having a five-valve-per-cylinder head increases valve area by 20 percent over an optimized four-valve design. Envision, if you will, cutting round cookies out of a circle of dough. Cut four round cookies, and you will have a fair amount of dough left over; cut five slightly smaller cookies out of a circle with the same diameter, and you will have less dough left over, or 20 percent more dessert. Five valves instead of four allow the engine to breathe more efficiently and produce more power, Audi says.

This approach works, and the improvement in acceleration is imme­diately noticeable. The 1998 A4 2.8 accelerates from 0 to 60 mph in 7.4 sec­onds and runs the quarter-mile in 15.9 seconds at 89 mph (last year, the equiv­alent two-valve A4 engine ran 8.1 and 16.2, respectively). The five-valve V-6 pulls strongly to the redline at 6300 rpm—right where the previous motor started running out of breath. However, the variable-valve-timing and intake-runner systems brighten response at lower rpm as well, reducing 30-to-50-mph and 50-to-70-mph top-gear acceleration times by about a second.

Keeping fuel consumption, emissions levels, and costs low while still adding power and torque were all key ingredients in choosing the five-valve approach, according to Weps. Adding horsepower is easily done, but Audi's goal was to accom­plish this without sacrificing fuel economy or increasing emissions. EPA mileage esti­mates for the 1998 A4 2.8 Quattro are 19 and 27 mpg for city and highway driving, which is up one digit on the highway scale from the previous model's. And consid­ering that the base price of a 1998 30-valve A4 is $28,620—only $690 more than the 1997 12-valve A4 V-6 model—we think the increase in price is justifiable.

The only other automaker offering this five-valve technology is Ferrari. Just how valuable is adding valves as opposed to increasing displacement, or reducing weight, or reworking the gear ratios, or any number of other strategies that can be employed to improve an engine? The 2.8-liter inline six-cylinder engine in the BMW 328i makes an almost identical 190 horsepower and 206 pound-feet of torque with just four valves per cylinder, so it would appear that, for BMW, the added cost and complexity of adding the valves might not be worth the investment. But as a means of boosting the power and low­-end torque of an existing engine, five­-valve heads clearly made sense for Audi.

Audi's other A4, the 150-horsepower turbocharged four-cylinder 1.8T, takes almost a second longer to get from 0 to 60 (8.3 seconds) and feels far less smooth and refined than the 2.8 V-6, but it also costs $5130 less. Audi says sales have been split about 55/45, with the slight edge going to the V-6 models.

As equipped, our A4 2.8 cost $33,150. That price included a $400 Sport package with Michelin Pilot HX tires, seven-spoke 16-inch wheels, a three-spoke steering wheel that looks great and feels good in your hands, and a suspension that has been lowered 20 millimeters and fitted with firmer shocks and springs. Handsome burled-walnut dash and door trim panels are standard, as are front-seat-mounted side airbags.

Also included were the all-wheel-drive Quattro system for $1600 and a $630 All Weather package with headlamp washers, heated front seats, and a ski sack in the rear-seat armrest that prevents dirt and snow from dripping off skis and onto the rear seats. A $250 trip computer features a helpful speed reminder for drivers who can't afford another speeding ticket. You can set a speed-limit alarm into the com­puter, and when that speed is exceeded by 6 mph, a tone will sound. It's a valuable feature for some non-radar-detector users around here.

All things considered, the A4 feels like a lot of car for the money. The A4, along with the all-new A8 and the upcoming A6, have given Audi a second wind in the luxury-car race, and sales figures reflect this. In the first five months of 1996, Audi sold 6305 A4s. During the same period in 1997, Audi sold 9017—an increase of 43 percent. And in May, Audi's sales as a whole were up 45 percent over last year's. We expect this five-valve 2.8 to accelerate that trend.

I had four errands to run along a circuitous 100-mile route. I left the office at 5:15 and was expected for dinner at 7:30. This was to be one of those cut-and-thrust, row-the­-gearbox, bat-out-of-hell commutes. Audi's new deep-breathing 30-valve V-6 makes the '98 A4 perfect for such a mission. Speed and revs build much more quickly now, as if the gearing had been shortened (it hasn't). At 5000 rpm, the cam timing and intake geometry change, unleashing a VTEC-like surge of power to the redline. In short, this engine now feels as agile and energetic as the A4 chassis always has. I even arrived in time for a before-dinner drink. —Frank Markus

In the spring of '95, I drove the brand-new Audi A4 Quattro from Germany to Hun­gary for a first look at a U.S.-spec car, ending the trip at an Audi engine plant being built at Győr. Audi wasn't exactly apologetic that the A4 had the Audi 90's carryover 2.8-liter 12-valve V-6, but the company promised a 30-valve V-6 for the 1998 model year. Obvi­ously, it's delivered. Although the A4 still isn't a drag racer, this new version of the V-6 is tractable and sewing-machine smooth. The A4 came to America as a great car with a good engine. Now? Great car, great engine. —Steven Cole Smith

Specifications

1998 Audi A4 2.8Vehicle Type: front-engine, all-wheel-drive, 5-passenger, 4-door sedan

PRICEBase/As Tested: $28,620/$33,150Options: Quattro system, $1600; glass sunroof and remote-locking package, $1190; All Weather package (consists of heated windshield, front seats, washer nozzles, and driver-door lock; ski sack), $630; Pelican Blue metallic paint $460; Sport package (consists of 7-spoke aluminum wheels, 205/55ZR-16 tires, sport suspension and steering wheel), $400; trip computer, $25

ENGINEDOHC 30-valve V-6, iron block and aluminum heads, port fuel injectionDisplacement: 169 in3, 2769 cm3Power: 190 hp @ 6000 rpmTorque: 207 lb-ft @ 3200 rpm

TRANSMISSION5-speed manual

CHASSISSuspension, F/R: multilink/control armsBrakes, F/R: 10.9-in vented disc/9.6-in discTires: Micheln Pilot HX205/55ZR-16

DIMENSIONS Wheelbase: 102.6 inLength: 178.0 inWidth: 68.2 inHeight: 55.8 inPassenger Volume, F/R: 48/37 ft3Trunk Volume: 14 ft3Curb Weight: 3361 lb

C/D TEST RESULTS60 mph: 7.4 sec1/4-Mile: 15.9 sec @ 89 mph100 mph: 20.9 sec120 mph: 33.1 secRolling Start, 5–60 mph: 8.2 secTop Gear, 30–50 mph: 10.0 secTop Gear, 50–70 mph: 9.2 secTop Speed (gov ltd): 128 mphBraking, 70–0 mph: 175 ftRoadholding, 300-ft Skidpad: 0.87 g

C/D FUEL ECONOMYObserved: 22 mpg

EPA FUEL ECONOMYCity/Highway: 19/27 mpg

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