What are the performance statistics for a 1978 Porsche 928
Executive summary
The 1978 Porsche 928 was a front‑engine, water‑cooled V8 grand tourer whose factory ratings and contemporary road‑test numbers place it squarely in the high‑performance GT class of its day: a 4.5‑litre V8 producing roughly 219 hp (U.S.) or 237–240 hp (European), sprinting to 60 mph in the mid‑6‑second range and weighing just over 3,400 lb (curb) [1] [2] [3]. Period testers and modern spec compilations emphasize its balanced transaxle layout and competitive straight‑line performance while noting its heavier curb weight versus Porsche’s traditional 911 [4] [3].
1. Powerplant and claimed output
Porsche equipped the 1978 928 with a 4,474 cc (4.5 L) water‑cooled V8; European ratings for the early 16‑valve engine are commonly given as about 240 PS (≈237 hp / 176.5 kW) while the North American SAE‑net figure is typically cited as 219 hp (163 kW) for 1978 models intended for that market [1] [2] [5]. Torque figures reported in period and compiled specs show roughly 350 N·m (≈258 lb‑ft) for the European specification and about 344 N·m (≈254 lb‑ft) for North American versions [1] [5].
2. Acceleration and quarter‑mile performance
Independent test data and later aggregators converge on mid‑6‑second 0–60 mph performance: Car & Driver’s 1978 test returned 0–60 mpg in about 6.4 seconds while European‑spec performance calculators give roughly 6.3 s for the 5‑speed manual car [3] [6]. Quarter‑mile times recorded in contemporary tests and retrospective databases are in the mid‑15‑second range, commonly cited around 14.9–15.3 seconds at roughly 92–93 mph trap speed [6] [3].
3. Top speed, weight and stopping
Period road‑test write‑ups and spec sheets place the 928’s top speed in the high‑130s to low‑150s mph for European‑spec cars; the exact figure varies with gearing and market specification, and not all sources quote a single authoritative top‑speed number [1] [6]. Curb weight reported by Car & Driver for a tested 1978 example is about 3,420 lb, a factor that helps explain why performance was similar to contemporary 911 models despite the 928’s greater displacement and modern chassis layout [3] [4]. Braking figures from the era include 70–0 mph distances reported around 182 ft in Car & Driver testing [3].
4. Transmission, drivetrain layout and how that shapes performance
The 928 used either a five‑speed manual (dog‑leg pattern on many early cars) or a three‑speed Mercedes‑derived automatic in 1978, paired to a rear transaxle that Porsche used to achieve near 50/50 front/rear weight distribution — a key contributor to its GT handling balance [4]. Gearbox choice and final drive ratios influenced both measured acceleration and factory‑quoted top speeds, and the majority of 1978–79 cars were fitted with the five‑speed manual while automatics were less common [4].
5. Handling character and real‑world performance context
Beyond numbers, period reviewers praised the 928 for its power‑assisted steering with speed‑sensitive boost, four‑wheel independent suspension, Weissach axle geometry at the rear and all‑round disc brakes — elements that made the heavy V8 coupe feel more like a balanced grand tourer than a raw sports car [7] [8]. The car’s performance package and design won the 1978 European Car of the Year award and contemporary testers said its on‑road performance made many rivals feel dated, even if the 928 didn’t chase extreme lightness [4] [8].
Conclusion: numbers that match the character
Measured and factory statistics for the 1978 Porsche 928 paint a coherent picture: a 4.5‑L V8 GT with roughly 219 hp in U.S. tune (≈237–240 hp in Europe), mid‑6‑second 0–60 mph times, mid‑15‑second quarter miles, substantive curb weight just over 3,400 lb, and chassis features (transaxle, suspension, steering) that delivered handling commensurate with its straight‑line capability — all of which explain why it was viewed as a game‑changing Porsche in 1978 [2] [1] [3] [4] [7].