1985 Porsche 928S
Faster is better.
ARCHIVED INSTRUMENTED TEST
From the May 1985 Issue of Car and Driver
TESTED
"The old man would spin in his grave if he saw what they're passing off as a Porsche these days," raved the gas-station attendant. "They've lost the original concept. Where's the rear engine? Where's the air cooling?" Our rebuttal, emphasizing the performance virtues of the 1985-model 928S, failed to sway the man's thinking one iota. To the pump jockey and to many enthusiasts, the only real Porsches are those that perpetuate the design themes of the original 356 model, a car born nearly 40 years ago.
That's a shame, because the good doctor would doubtless be proud of this new 928S. Ferdinand Porsche believed that a sports car must offer transportation superior to a regular sedan's, and this doctrine is a cornerstone of the firm that bears his name today. Sports cars necessarily have smaller payloads than sedans, but for this reason they can be more fuel-efficient and be designed for higher speeds. And, unlike our federal government, Porsche has always understood that, in transportation, faster is better. Jet aircraft have replaced ocean liners and trains for long-distance travel; people drive cars instead of riding bicycles; and even bicycles are faster than they used to be. Faster transportation, simply put, is better transportation.
By the speediness criterion, the 1985 Porsche 928S is a substantial improvement over its predecessor. Top speed is up 10 mph, to 154. Our five-speed test car rocketed from a standing start to 60 mph in 5.7 seconds and hit 100 mph less than eight seconds later; the old car required 6.2 and 17.8 seconds, respectively. And the new model burned through the standing quarter-mile in 14.0 seconds at 102 mph, compared with 14.7 seconds at 94 mph for last year's 928. We also tested the automatic version, and its performance is similarly improved. The automatic's 0-to-60 and quarter-mile times now match those of last year's five-speed, and its top speed is up 10 mph, to 152.
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These are amazing figures for a car with extremely tall, fuel-economy-oriented gearing and more than enough power to break the tires loose at low speeds. Credit for the improvements belongs to the new 5.0-liter V-8 engine. With 288 bhp, it's a hefty 54 bhp stouter than the previous 928's 4.7-liter engine, which wasn't what you'd call a weakling. To put this brawn into proper perspective, the new motor makes one-third more power than Chevrolet's fuel-injected V-8 of the same displacement and 104 bhp more than Mercedes' American-specification 5.0-liter V-8.
Even more remarkable than this lofty power output is the Porsche V-8's broadband torque. Although the 302-pound-foot peak occurs at a relatively low 2700 rpm, more than 250 pounds-feet is on hand from 1300 to over 6000 rpm. Most 5.0-liter V-8s do well to exceed that level at any engine speed.
This engine magic is the direct result of the new four-valve-per-cylinder, twin-cam heads (C/D, February 1985). The four-valve layout provides good high-rpm breathing, ensuring plenty of power. This in turn allowed Porsche's powertrain engineers to tune the engine's manifolding and valve timing for efficient low- and medium-rpm breathing, providing good torque. The four-valve design also has a pent-roof combustion chamber with a centrally located spark plug, a design that resists detonation and promotes thermodynamically efficient combustion. Consequently, a high compression ratio (10.0:1) could be employed, enhancing both fuel economy and power output at all rpm.
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EPA fuel-economy figures have improved slightly from last year's, so the 928S will stay off the dreaded gas-guzzler rolls. Still, with its 18-mpg over-the-road mileage, this car won't be of much interest to fuel misers. The 928S's efficiency improvements are significant, though, because they are true to the Porsche philosophy that cars are transportation tools. As the company credo goes, fuel efficiency is important to the transportation function and should never be sacrificed, not even for higher performance.
It's good that the firm feels strongly about this, because once a 928S is in the hands of a customer, a touch of the accelerator will wipe out any interest in fuel economy. Not only can the driver effortlessly dial up just about any speed he desires, but the tall gearing and the broad output offer several alternatives to how he goes about his business. To effect nearly instantaneous speed changes, one uses the lower gears, even at very high speeds. Or one can remain exclusively in fifth from about 30 mph and still outpace most traffic. (Since the 928's shift linkage is still not a strong point, this approach is quite attractive.) Or one can specify the four-speed automatic, which always seems ready to transform the engine's plentiful power into blinding speed, requiring only an effortless touch on the accelerator.
