The BMW E9 3.0CS Automatic, produced between April 1971 and October 1975, represents a significant iteration of the E9 coupe series. Positioned as a luxurious grand tourer, the 3.0CS aimed to blend performance with comfort, appealing to buyers seeking a sophisticated and capable vehicle. This variant, equipped with a 3.0-liter inline-six engine and a three-speed automatic transmission, occupied a middle ground within the E9 lineup, offering a more relaxed driving experience compared to the manual transmission models while still delivering respectable performance. It was a key model in establishing BMW’s reputation for building driver-focused, yet refined automobiles in the North American market, where the E9 coupes were particularly well-received.
Technical Specifications
| Brand | BMW |
| Model | E9 |
| Generation | E9 |
| Type (Engine) | 3.0CS (180 Hp) Automatic |
| Start of production | April, 1971 |
| End of production | October, 1975 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (economy) – extra urban | 8.5 l/100 km (27.7 US mpg, 33.2 UK mpg, 11.8 km/l) |
| Fuel consumption (economy) – combined | 11.2 l/100 km (21 US mpg, 25.2 UK mpg, 8.9 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 8.2 sec |
| Acceleration 0 – 62 mph | 8.2 sec |
| Acceleration 0 – 60 mph | 7.8 sec |
| Maximum speed | 207 km/h (128.62 mph) |
| Weight-to-power ratio | 7.9 kg/Hp, 126.8 Hp/tonne |
| Weight-to-torque ratio | 5.5 kg/Nm, 183.1 Nm/tonne |
| Power | 180 Hp @ 6000 rpm |
| Power per litre | 60.3 Hp/l |
| Torque | 260 Nm @ 3700 rpm (191.77 lb.-ft. @ 3700 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M30B30V |
| Engine displacement | 2985 cm3 (182.16 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 89 mm (3.5 in.) |
| Piston Stroke | 80 mm (3.15 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 | 5.75 l (6.08 US qt, 5.06 UK qt) |
| Coolant | 12 l (12.68 US qt, 10.56 UK qt) |
| Kerb Weight | 1420 kg (3130.56 lbs.) |
| Max. weight | 1790 kg (3946.27 lbs.) |
| Max load | 370 kg (815.71 lbs.) |
| Trunk (boot) space – minimum | 450 l (15.89 cu. ft.) |
| Fuel tank capacity | 72 l (19.02 US gal, 15.84 UK gal) |
| Max. roof load | 75 kg (165.35 lbs.) |
| Permitted trailer load with brakes (12%) | 1300 kg (2866.01 lbs.) |
| Permitted trailer load without brakes | 650 kg (1433 lbs.) |
| Length | 4660 mm (183.46 in.) |
| Width | 1670 mm (65.75 in.) |
| Height | 1370 mm (53.94 in.) |
| Wheelbase | 2625 mm (103.35 in.) |
| Front track | 1446 mm (56.93 in.) |
| Rear (Back) track | 1402 mm (55.2 in.) |
| Minimum turning circle (turning diameter) | 10.5 m (34.45 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 | 3 gears, automatic transmission |
| Front suspension | Double wishbone, Transverse stabilizer |
| Rear suspension | Independent coil spring, Trailing arm |
| Front brakes | Ventilated discs, 272 mm |
| Rear brakes | Ventilated discs, 272 mm |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | 195/75 R14 |
| Wheel rims size | 6J x 14 |
Powertrain & Engine Architecture
The heart of the E9 3.0CS Automatic is the M30B30V engine, a 2.985-liter (182.16 cubic inches) inline-six cylinder powerplant. This engine, a hallmark of BMW engineering during the 1970s, featured a single overhead camshaft (SOHC) valvetrain operating two valves per cylinder. Unlike later BMW engines that embraced fuel injection, the 3.0CS utilized twin Solex carburetors for fuel delivery. This carburetor setup, while providing smooth power delivery, was less efficient and more sensitive to altitude and temperature changes compared to fuel injection systems. The engine produced 180 horsepower at 6000 rpm and 260 Nm (191.77 lb-ft) of torque at 3700 rpm. The engine’s longitudinal mounting and rear-wheel-drive configuration were standard for BMW at the time, contributing to the car’s balanced handling characteristics.
The automatic transmission paired with the M30B30V was a three-speed unit. While offering convenience, this transmission wasn’t known for its sporty responsiveness. The gear ratios were optimized for comfortable cruising rather than aggressive acceleration. The automatic transmission contributed to a slightly heavier overall vehicle weight and a marginally slower 0-60 mph time compared to the manual transmission versions.
Driving Characteristics
The E9 3.0CS Automatic offered a refined and comfortable driving experience. The automatic transmission smoothed out the power delivery of the inline-six, making it an excellent grand tourer. Acceleration, while respectable at around 8.2 seconds for 0-100 km/h (0-62 mph), wasn’t as brisk as the manual transmission models. The three-speed automatic meant that the engine often operated at higher rpm during highway cruising, potentially impacting fuel economy. The car’s weight, approximately 1420 kg (3130.56 lbs), was noticeable, particularly during cornering, but the well-tuned suspension helped to mitigate body roll. The hydraulic power steering provided a light and easy steering feel, enhancing the car’s usability in urban environments.
Equipment & Trim Levels
The 3.0CS Automatic came standard with a relatively high level of equipment for its time. Interior features included comfortable cloth or leather upholstery (leather was optional), wood trim on the dashboard and door panels, and a comprehensive instrument cluster. Standard features also included power-assisted brakes, a heater, and a basic sound system. Optional extras included air conditioning, a sunroof, and upgraded audio systems. The trim level was generally consistent across the 3.0CS Automatic models, with variations primarily stemming from the selection of optional equipment.
Chassis & Braking
The E9 3.0CS featured a robust chassis with independent suspension all around. The front suspension utilized a double wishbone design with a transverse stabilizer bar, while the rear suspension employed a trailing arm setup with coil springs. This suspension configuration provided a good balance between ride comfort and handling. Braking duties were handled by ventilated disc brakes on all four wheels, offering adequate stopping power for the car’s weight and performance. The steering system was a cone worm with recirculation balls, providing a relatively direct steering feel.
Market Reception & Comparison
The E9 3.0CS Automatic was generally well-received by automotive critics. It was praised for its elegant styling, comfortable interior, and refined driving experience. However, the automatic transmission was sometimes criticized for its lack of responsiveness compared to the manual gearbox. Compared to the 3.0CS with a manual transmission, the automatic version offered a more relaxed driving experience but sacrificed some performance. The 3.0CS also differed significantly from the 2.8CS, offering more power and torque, and a larger engine displacement. Fuel economy, at around 11.2 l/100 km (21 US mpg), was typical for a car of its size and performance in the 1970s.
Legacy
The BMW E9 3.0CS Automatic remains a sought-after classic car today. The M30 engine, while carbureted, is known for its durability and relatively straightforward maintenance. However, finding parts for these older BMWs can be challenging and expensive. The automatic transmission, while reliable, may require periodic servicing. The E9 3.0CS Automatic represents a pivotal moment in BMW’s history, showcasing the company’s commitment to building luxurious and capable grand tourers. Its elegant design and refined driving experience continue to appeal to enthusiasts and collectors alike, ensuring its place as a significant automobile of the 1970s.
