The BMW 730, produced between 1977 and 1979, represents the entry point into the first generation (E23) of BMW’s flagship 7 Series luxury sedan. Positioned below the 733i and later the 735i, the 730 was designed to offer a taste of the 7 Series experience to a broader clientele, prioritizing fuel efficiency and a more accessible price point within the luxury market. It served as a crucial model in establishing the 7 Series as a competitor to Mercedes-Benz’s S-Class and other premium sedans. The E23 platform, known for its advanced engineering and focus on driver experience, laid the foundation for all subsequent 7 Series generations.
Technical Specifications
| Brand | BMW |
| Model | 7 Series |
| Generation | 7 Series (E23) |
| Type (Engine) | 730 (184 Hp) |
| Start of production | 1977 |
| End of production | 1979 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 9.6 sec |
| Acceleration 0 – 62 mph | 9.6 sec |
| Acceleration 0 – 60 mph | 9.1 sec |
| Maximum speed | 200 km/h (124.27 mph) |
| Weight-to-power ratio | 8.6 kg/Hp, 116.5 Hp/tonne |
| Weight-to-torque ratio | 6.2 kg/Nm, 161.4 Nm/tonne |
| Power | 184 Hp @ 5500 rpm |
| Power per litre | 61.6 Hp/l |
| Torque | 255 Nm @ 3500 rpm (188.08 lb.-ft. @ 3500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | 306VZ1 |
| 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 | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | SOHC |
| Engine oil capacity | 5.8 l (6.13 US qt | 5.1 UK qt) |
| Kerb Weight | 1580 kg (3483.3 lbs.) |
| Max. weight | 2050 kg (4519.48 lbs.) |
| Max load | 470 kg (1036.17 lbs.) |
| Fuel tank capacity | 90 l (23.78 US gal | 19.8 UK gal) |
| Length | 4860 mm (191.34 in.) |
| Width | 1800 mm (70.87 in.) |
| Height | 1430 mm (56.3 in.) |
| Wheelbase | 2795 mm (110.04 in.) |
| Front track | 1502 mm (59.13 in.) |
| Rear (Back) track | 1524 mm (60 in.) |
| Ride height (ground clearance) | 132 mm (5.2 in.) |
| 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 suspension | Independent, type McPherson with coil spring and anti-roll bar |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Tires size | 205/70 R14 |
| Wheel rims size | 6.5J x 14 |
Powertrain & Engine Architecture
The heart of the 730 is the M30 inline-six cylinder engine, specifically the 306VZ1 variant. This 3.0-liter engine, while sharing the basic architecture with the larger 3.3 and 3.5-liter versions found in the 733i and 735i respectively, was detuned to produce 184 horsepower at 5500 rpm and 255 Nm (188 lb-ft) of torque at 3500 rpm. The engine utilizes a single overhead camshaft (SOHC) valvetrain operating four valves per cylinder. Fuel delivery is managed by a Bosch multi-port fuel injection system, a relatively advanced feature for the late 1970s, contributing to improved fuel efficiency and smoother operation compared to carbureted engines. The engine’s longitudinal mounting and rear-wheel drive configuration were standard for BMW at the time, emphasizing a balanced chassis and engaging driving experience. The 730 was exclusively offered with a four-speed manual transmission, a deliberate choice to keep costs down and appeal to drivers who preferred a more involved driving experience.
Driving Characteristics
The 730’s driving experience is characterized by a blend of comfort and respectable performance. While not as overtly powerful as its larger-engined siblings, the 3.0-liter inline-six provides sufficient power for comfortable cruising and confident overtaking. The four-speed manual transmission allows for precise control over the engine’s powerband. Acceleration from 0 to 60 mph takes approximately 9.1 seconds, and the car reaches a top speed of 200 km/h (124 mph). Compared to the 733i and 735i, the 730 feels less urgent in its acceleration, but the lower weight (1580 kg) contributes to a more nimble feel in corners. The gear ratios are well-chosen for everyday driving, providing adequate torque in each gear. The suspension, featuring McPherson struts at the front and a multi-link setup at the rear, delivers a comfortable ride while maintaining good handling characteristics.
Equipment & Trim Levels
The 730, as the entry-level model, came standard with a respectable level of equipment, though it was less lavishly appointed than the higher-spec versions. Standard features included cloth upholstery, power windows, central locking, and a basic radio. Air conditioning was often an optional extra, as were leather upholstery, a sunroof, and upgraded sound systems. The dashboard layout was typical of BMW in the late 1970s, featuring a driver-focused design with clearly marked gauges and controls. The interior trim was generally conservative, reflecting the car’s more affordable positioning. While not as luxurious as the 733i or 735i, the 730’s interior still offered a sense of quality and refinement.
Chassis & Braking
The E23 7 Series chassis is a robust and well-engineered structure. The 730 utilizes independent suspension all around, with McPherson struts at the front and a multi-link setup at the rear. This configuration provides a good balance between ride comfort and handling precision. The braking system consists of ventilated discs at the front and solid discs at the rear, providing adequate stopping power for the car’s weight and performance. Power steering was standard, making the car easy to maneuver at low speeds. The 730’s suspension setup is tuned for comfort, but it still offers a reasonably controlled and engaging driving experience. Stabilizer bars are fitted front and rear to reduce body roll during cornering.
Market Reception & Comparison
The BMW 730 was generally well-received by automotive critics, who praised its comfortable ride, refined engine, and relatively affordable price. However, some critics noted that it lacked the outright performance of the 733i and 735i. Compared to its siblings, the 730 offered a more economical option for buyers who wanted the prestige of a 7 Series without the higher price tag. Fuel economy was a key selling point, particularly in the late 1970s when fuel prices were rising. The 730’s reliability was also considered to be good, although maintenance costs could be relatively high due to the car’s complex engineering.
Legacy
The BMW 730 (E23) holds a significant place in BMW’s history as the entry point to the first generation of the 7 Series. While not as sought-after as the higher-performance models, the 730 remains a desirable classic car for enthusiasts. The M30 engine is known for its durability and relatively straightforward maintenance. Today, well-maintained examples of the 730 are becoming increasingly rare and valuable. The car’s combination of classic BMW styling, comfortable ride, and reliable engine makes it a rewarding ownership experience for those who appreciate a piece of automotive history. The 730’s success helped establish the 7 Series as a benchmark for luxury sedans, a reputation that continues to this day.
