1990 Porsche 928GT Archive Road Test: Speed for the Solvent

From the July 1990 issue of Car and Driver.

So there you are with a spare $76,500 in your pocket and an itch in your brain. Your plans to invest in flight lessons have been dashed (who’d have guessed that the FAA would object to your building a backyard dirigible hangar?). Your art col­lection is looking plenty comprehensive already—you’ve yet to figure out if you even have a wall big enough for the JFK­-assassination acrylic. And only yesterday you found out that the neighborhood has zoning laws prohibiting the ranching of African gnus. Either you come up with a big-money diversion fast or the cash is going to have to go in the bank.

Allow us to suggest a quick remedy: the Porsche 928GT. If you have more money than encumbrances, you’ll want to take a look at this brawny automotive toy. And we do mean toy. So committed to speed is this latest version of the 928 that it makes casual cruising almost un­pleasant. In fact, if it’s high-comfort, high-exposure profiling you’re after, you might as well stop reading right now.

What’s that? Isn’t this the famed 928 we’re talking about—the Porsche of choice among the country-club set? Well, yes. And that’s precisely why we thought we should have this little talk.

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Introduced in 1978, the 928 has always been a serious sporting machine. Yet its luxury fittings and versatile GT profile have earned it a reputation as something of a poseur’s Porsche—a car seen less of­ten carving up mountain roads than be­ing proudly handed over to the country-­club valet. That’s not Porsche’s fault: over the years the maker has steadily im­proved the 928 to keep it near the top of the performance class. In fact, the new manual-gearbox-only GT edition shown here is the most speed-dedicated 928 yet. But that brings us back to our warning: anyone who buys a GT looking for relax­ing daily transportation is in for a shock.

The GT is a deadly serious driver’s car. In its quest for pure performance, Porsche has chiseled off most of the 928’s remaining soft edges.

There are engine refinements, of course. The GT’s 5.0-liter V-8 benefits from new camshafts and a retuned intake system; the changes increase the output of the four-cam, 32-valve engine by 10 horsepower, to 326 at 6200 rpm. The automatic-equipped 928S4, on the other hand, produces the same 316 hp as last year’s S4. The GT makes the same maxi­mum torque as the S4—317 pound-­feet-but its torque peak is 4100 rpm, 1100 rpm higher.

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The extra power shows on the stop­watch. The GT rockets from 0 to 60 mph in just 5.2 seconds and through the quarter-mile in 13.7 seconds at 104 mph—improvements of 0.1 and 0.2 sec­ond, respectively, over the times generat­ed by the five-speed 928S4 we tested in May 1987. (Not a bad showing for a 3603-pound “luxury” GT, eh?) Top speed is up a full 10 mph, to 169 mph at the engine’s 6600-rpm redline.

You don’t need a stopwatch to appre­ciate this kind of performance. Step hard into the throttle at almost any rpm and the GT hurtles forward, the V-8 pulling with particular vigor as it ticks over the 4000-rpm mark. (The V-8’s full-throttle cry, by the way, could raise the hair of a Vitalis devotee.) Wind the engine to the redline in first gear and you’ll hit 45 mph. Wind it out in second and you’ll muster enough speed to secure the attention of any nearby highway patrolman.

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The 928GT shines when you give it the spurs. The control efforts are finely honed for speeds above 80 mph: the steering arcs with reassuring heft, the shifter chunks solidly through its racing-pattern H, and the clutch takeup is smooth and positive. Spin the speedo up to autobahn speeds and the GT really comes into its own. Suddenly, the beefy body feels not chubby but secure; racing across the pavement at the velocities al­lowed in its homeland, the GT feels like a locomotive built for two.

The GT is far more agile in curvy-road dicing and slicing than you’d expect such a hefty car to be. Porsche has tamed the old 928’s tail-happiness; the GT under­steers resolutely through hard bends, tucking in neatly even if you suddenly snap off the throttle (it’s still possible to kick the tail out with a sharp jab on the power). The four fat Bridgestone RE71s—225/50ZR-16s in front and 245/45ZR-16s in back-display com­mendable friction in corners: the GT cir­cles the skidpad at 0.86 g.

To improve the relationship between tire and earth, both 1990-model 928s sport Porsche’s electronically controlled limited-slip differential—a device first seen on the mighty 959. At the heart of the system is a progressively lockable multiplate clutch in-unit with the rear dif­ferential. A computer gradually engages the clutch when it detects any wheelspin at the rear; in so doing, it helps each rear tire transmit as much power as its avail­able traction will allow. A small indicator light on the dash glows whenever the sys­tem is activated.

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The GT’s massive ABS-equipped disc brakes are simply superb, hauling the car down from 70 mph in just 167 feet. Fade is simply not an issue, even after repeated hard stops.

Before your performance-hungry eyes glaze over completely, however, you need to know that this stirring perfor­mance exacts a toll. There’s no question that if you drive the 928GT hard—really hard—it’ll reward you with some of the best moves in the auto kingdom. But if your driving is dominated by strolls over to the polo club, you’re likely to think of the GT as more beast than beauty.

The GT’s ride is, in a word, firm. Over the sort of fractured asphalt that blem­ishes most of Michigan, the car ham­mers and crashes so badly that you won­der if there’s any suspension under your rear end. (Imagine riding down a log pile in an iron canoe and you’ll be close.) The RE71s—not known as particularly smooth-riding tires—con­tribute to the harshness, as does the shock valving, which Porsche has firmed up for 1990. The unforgiving ride isn’t the only strain: the shifter, the clutch, and the steering—so exemplary at high speeds—feels heavy and ponderous in city cruising. Driving the GT at six-tenths or less is work. Rough work.

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Followers of the 928 will note that the interior is familiar (a new low-tire-pres­sure warning system has been added to the driver-information display). It’s a fine cabin, simple and businesslike, but it’s se­vere. You sit low, surrounded by high sills and a tall center console. All around you are stern, sensible gauges and no­-nonsense controls. There isn’t a sooth­ing detail in sight. It’s a great place from which to conduct the business of serious driving, but it’s not going to do anything to brighten your mood as you thunk your way over to the club.

That’s not to imply that the GT is stark. The standard-equipment list cov­ers every imaginable power option, from heated outside mirrors and an auxiliary rear air conditioner to a ten-speaker AM/FM/cassette system—everything you’d expect in a luxury car. Then again, for $76,500, the 928GT had better be able to give the space shuttle a run for the “Best-­Equipped Vehicle” title.

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So you now realize that the 928GT is a damn serious automobile, requiring a se­rious investment and delivering serious performance. But the question remains: are you that serious? Since the 928’s de­but, a host of new and talented offerings have appeared in the luxury-GT class—cars that offer serious speed and day-to­-day civility. Of these, the standout is the new Nissan 300ZX Turbo—a car that de­livers much of the 928GT’s performance without the comfort penalty. And the Nissan costs $33,000. Do the addition and you’ll realize that for the price of a 928GT you could have a 300ZX Turbo, a Lexus LS400 sedan, and enough left over for a respectable European tour. Order some of the more extravagant options—such as a custom-colored leather interior and matched-to-sample exterior paint—and you can push the price of a GT over $100,000.

Porsche plans to sell only about 100 928GTs in the U.S. this year. That should tell you plenty about this car’s mass-market appeal.

The 928GT is a plaything—a leather-­lined speed machine for the very well heeled. If you’re looking for distinctive daily transportation and you have the GT on your short list, scratch it off—it’s far too unforgiving for that. But if you’ve got your daily wheels and you can afford to indulge in something frivolous, well, yes, you absolutely ought to consider this po­tent Porsche.

Besides, it’s a hell of a lot easier to park than a dirigible.

Specifications

Specifications

1990 Porsche 928GT
Vehicle Type: front-engine, rear-wheel-drive, 2+2-passenger, 3-door coupe

PRICE

Base/As Tested: $76,500/$76,500

ENGINE
DOHC 32-valve V-8, aluminum block and heads, port fuel injection
Displacement: 303 in³, 4957 cm³
Power: 326 hp @ 6200 rpm
Torque: 317 lb-ft @ 4100 rpm 

TRANSMISSION
5-speed manual

CHASSIS

Suspension, F/R: control arms/control arms
Brakes, F/R: 12.0-in vented disc/11.8-in vented disc
Tires: Bridgestone Potenza RE71

F: 225/50ZR-16
R: 245/45ZR-16

DIMENSIONS

Wheelbase: 98.4 in
Length: 178.1 in
Width: 72.3 in
Height: 50.5 in
Passenger Volume, F/R: 53/21 ft³
Cargo Volume: 6 ft³
Curb Weight: 3603 lb

C/D TEST RESULTS

60 mph: 5.2 sec
100 mph: 12.6 sec
1/4-Mile: 13.7 sec @ 104 mph
130 mph: 23.3 sec
150 mph: 39.2 sec
Top Gear, 30–50 mph: 7.1 sec
Top Gear, 50–70 mph: 7.2 sec
Top Speed: 169 mph
Braking, 70–0 mph: 167 ft
Roadholding, 300-ft Skidpad: 0.86 g

Interior Sound
Idle: 55 dBA
Full Throttle: 87 dBA
70-mph Cruising: 76 dBA

C/D FUEL ECONOMY

Observed: 13 mpg

EPA FUEL ECONOMY
City/Highway: 13/19 mpg 

C/D TESTING EXPLAINED