The Opel Commodore B Coupe 2.8 GS, produced between 1975 and 1978, represented a high-performance variant within the Commodore B Coupe range. Positioned as a grand tourer, it aimed to deliver a blend of style, comfort, and respectable performance. The Commodore B series, launched in 1972, was Opel’s flagship model, intended to compete with larger, more luxurious vehicles from British and Swedish manufacturers. The Coupe body style, introduced alongside the four-door sedan and station wagon, offered a more sporting aesthetic. The 2.8 GS trim, with its larger engine and upgraded features, sat at the top of the Coupe lineup, appealing to buyers seeking a more dynamic driving experience.
Technical Specifications
| Brand | Opel |
| Model | Commodore |
| Generation | Commodore B Coupe |
| Type (Engine) | 2.8 GS (140 Hp) |
| Start of production | 1975 |
| End of production | 1978 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 5 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 10.5 sec |
| Acceleration 0 – 62 mph | 10.5 sec |
| Acceleration 0 – 60 mph | 10 sec |
| Maximum speed | 190 km/h (118.06 mph) |
| Weight-to-power ratio | 8.9 kg/Hp, 112.9 Hp/tonne |
| Weight-to-torque ratio | 5.8 kg/Nm, 172.6 Nm/tonne |
| Power | 140 Hp @ 5200 rpm |
| Power per litre | 50.3 Hp/l |
| Torque | 214 Nm @ 3400-3800 rpm (157.84 lb.-ft. @ 3400-3800 rpm) |
| Engine Model/Code | 28HC |
| Engine displacement | 2784 cm3 (169.89 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 92 mm (3.62 in.) |
| Piston Stroke | 69.8 mm (2.75 in.) |
| Compression ratio | 9:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | SOHC |
| Engine oil capacity | 5.5 l (5.81 US qt | 4.84 UK qt) |
| Kerb Weight | 1240 kg (2733.73 lbs.) |
| Max. weight | 1675 kg (3692.74 lbs.) |
| Max load | 435 kg (959.01 lbs.) |
| Trunk (boot) space – minimum | 140 l (4.94 cu. ft.) |
| Fuel tank capacity | 70 l (18.49 US gal | 15.4 UK gal) |
| Length | 4607 mm (181.38 in.) |
| Width | 1728 mm (68.03 in.) |
| Height | 1380 mm (54.33 in.) |
| Wheelbase | 2668 mm (105.04 in.) |
| Front track | 1450 mm (57.09 in.) |
| Rear (Back) track | 1400 mm (55.12 in.) |
| Ride height (ground clearance) | 140 mm (5.51 in.) |
| Drag coefficient (Cd) | 0.45 |
| Minimum turning circle (turning diameter) | 11.2 m (36.75 ft.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, manual transmission |
| Front brakes | Disc |
| Rear brakes | Disc |
Powertrain & Engine Architecture
The heart of the Commodore B Coupe 2.8 GS was the 28HC inline-six cylinder engine, displacing 2784cc (169.89 cubic inches). This engine featured a single overhead camshaft (SOHC) valvetrain operating two valves per cylinder. Fuel delivery was managed by a carburetor, a common setup for the era, though less efficient than fuel injection. The 28HC produced 140 horsepower at 5200 rpm and 214 Nm (157.84 lb-ft) of torque between 3400 and 3800 rpm. The engine’s 9:1 compression ratio was a compromise between performance and the fuel quality available at the time. The engine was paired with a four-speed manual transmission as standard, delivering power to the rear wheels. While an automatic transmission was offered on other Commodore B models, it wasn’t typically paired with the 2.8 GS due to performance considerations.
Driving Characteristics
The 2.8 GS offered a noticeable step up in performance compared to the lower-spec Commodore Coupes. Acceleration from 0 to 100 km/h (0-62 mph) took approximately 10.5 seconds, and it could achieve a top speed of 190 km/h (118 mph). The inline-six engine provided a smooth and relatively refined power delivery, with peak torque available in the mid-range. The four-speed manual transmission allowed for precise control, and the rear-wheel-drive configuration contributed to a balanced handling feel. Compared to the smaller-engined Commodore Coupes, the 2.8 GS felt more capable on open roads and during overtaking maneuvers. However, it wasn’t a particularly lightweight car, and its handling wasn’t as sharp as some contemporary sports coupes.
Equipment & Trim Levels
The “GS” designation indicated a higher level of equipment. Standard features included upgraded interior trim, often featuring cloth upholstery with a sporty pattern, and a wood-trimmed dashboard. Additional features often included a comprehensive instrument cluster, a leather-wrapped steering wheel, and a high-quality radio. Optional extras could include power windows, a sunroof, and upgraded suspension components. The Commodore B Coupe 2.8 GS was designed to offer a comfortable and well-equipped driving experience, appealing to buyers who valued both performance and luxury.
Chassis & Braking
The Commodore B Coupe utilized a traditional body-on-frame construction, providing a robust and durable chassis. The suspension consisted of independent front suspension with coil springs and a rigid rear axle with leaf springs. Disc brakes were fitted to all four wheels, providing adequate stopping power for the car’s weight and performance. The 2.8 GS often featured a thicker front stabilizer bar compared to lower-spec models, improving handling and reducing body roll. The steering was a recirculating ball system, which provided a relatively heavy but precise feel.
Market Reception & Comparison
The Commodore B Coupe 2.8 GS was generally well-received by automotive critics. It was praised for its smooth engine, comfortable ride, and stylish design. However, some critics noted its relatively high price and its somewhat dated technology compared to newer models from other manufacturers. Compared to the other engines in the Commodore B lineup, the 2.8 GS offered the best performance, but it also came with a higher fuel consumption. The smaller engines, such as the 2.5-liter, were more economical but lacked the same level of performance. The 2.8 GS was positioned as a premium offering, appealing to buyers who were willing to pay extra for a more refined and powerful driving experience.
Legacy
The Opel Commodore B Coupe 2.8 GS remains a popular classic car today, particularly among enthusiasts of 1970s European automobiles. The 28HC engine is known for its durability and relative simplicity, making it relatively easy to maintain. However, parts availability can be a challenge, and finding a well-preserved example can be difficult. The Commodore B Coupe 2.8 GS represents a significant chapter in Opel’s history, showcasing the company’s ability to produce stylish, comfortable, and reasonably powerful grand tourers. Its blend of classic styling, robust engineering, and respectable performance continues to appeal to collectors and enthusiasts alike, ensuring its place in automotive history.
