The BMW 728, produced between 1977 and 1979, was an early iteration of the E23 generation 7 Series, BMW’s flagship luxury sedan. Positioned as the entry-level model in the initial 7 Series lineup, the 728 offered a more accessible price point compared to the higher-specification 730 and 733i variants. It represented BMW’s attempt to balance luxury and performance with a slightly more economical engine option, primarily aimed at buyers who prioritized refinement and comfort over outright speed. The 728 was significant as the first 7 Series model, establishing the design language and technological features that would define the lineage for decades to come.
Technical Specifications
| Brand | BMW |
| Model | 7 Series |
| Generation | 7 Series (E23) |
| Type (Engine) | 728 (170 Hp) Automatic |
| 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 | 11.9 sec |
| Acceleration 0 – 62 mph | 11.9 sec |
| Acceleration 0 – 60 mph | 11.3 sec |
| Maximum speed | 186 km/h (115.58 mph) |
| Weight-to-power ratio | 9.1 kg/Hp, 109.7 Hp/tonne |
| Weight-to-torque ratio | 6.7 kg/Nm, 150.3 Nm/tonne |
| Power | 170 Hp @ 5800 rpm |
| Power per litre | 61 Hp/l |
| Torque | 233 Nm @ 4000 rpm (171.85 lb.-ft. @ 4000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | 286VZ1 |
| Engine displacement | 2788 cm3 (170.13 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 86 mm (3.39 in.) |
| Piston Stroke | 80 mm (3.15 in.) |
| Compression ratio | 9:1 |
| Number of valves per cylinder | 2 |
| 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) |
| Coolant | 12 l (12.68 US qt | 10.56 UK qt) |
| Kerb Weight | 1550 kg (3417.17 lbs.) |
| Max. weight | 2000 kg (4409.25 lbs.) |
| Max load | 450 kg (992.08 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 | 3 gears, automatic transmission |
| Front suspension | Independent, type McPherson with coil spring and anti-roll bar |
| Rear suspension | Independent coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Tires size | 195/70 HR14; 220/55 HR390 TRX |
| Wheel rims size | 6.0J x 14; 165 T 390 |
Powertrain & Engine Architecture
The heart of the 728 was the M286 engine, a 2.8-liter inline-six cylinder powerplant. This engine, designated as 286VZ1, featured a single overhead camshaft (SOHC) valvetrain operating two valves per cylinder. It utilized Bosch K-Jetronic multi-port fuel injection, a sophisticated system for its time, which contributed to improved fuel efficiency and smoother operation compared to carbureted engines. The 9:1 compression ratio was a compromise between performance and the ability to run on the available fuel grades of the era. The engine’s longitudinal front-engine layout, coupled with rear-wheel drive, was a classic BMW configuration. The three-speed automatic transmission, while providing convenience, was a key differentiator from the more driver-focused manual transmission options available in other 7 Series models.
Driving Characteristics
The 728’s performance was best described as refined and comfortable rather than sporty. With 170 horsepower and 172 lb-ft of torque, acceleration from 0 to 60 mph took around 11.3 seconds, and it reached a top speed of approximately 115.6 mph. Compared to the 730i and 733i, which offered significantly more power, the 728 felt noticeably slower, particularly during overtaking maneuvers. The automatic transmission, while smooth, contributed to a less engaging driving experience. The gear ratios were optimized for fuel economy and cruising comfort, rather than aggressive acceleration. However, the 728 still benefited from BMW’s renowned chassis tuning, providing a composed and stable ride even at higher speeds.
Equipment & Trim Levels
The 728, as the entry-level model, came standard with a respectable level of equipment. Interior appointments included cloth upholstery, although leather was available as an option. Standard features included power windows, central locking, and a basic radio. Air conditioning was a popular option, as was a sunroof. The dashboard layout was typical of BMW in the late 1970s, featuring a straightforward design with clearly marked gauges. Higher trim levels offered upgrades such as power-adjustable seats, upgraded sound systems, and more luxurious interior materials. The 728 aimed to provide a comfortable and well-equipped experience without the expense of the more premium options.
Chassis & Braking
The E23 7 Series featured an independent suspension system all around. The front suspension utilized a McPherson strut design with coil springs and an anti-roll bar, while the rear employed an independent coil spring setup. This configuration provided a good balance of ride comfort and handling. The 728 was equipped with ventilated disc brakes at the front and solid disc brakes at the rear, providing adequate stopping power for its weight and performance. The steering was a recirculating ball system, offering a relatively light and precise feel. The chassis was designed to be robust and durable, contributing to the E23’s reputation for longevity.
Market Reception & Comparison
The 728 was generally well-received by automotive critics, who praised its comfortable ride, refined interior, and relatively fuel-efficient engine. However, some reviewers noted its lack of outright performance compared to its more powerful siblings. The 728 offered a more affordable entry point into the 7 Series range, appealing to buyers who prioritized luxury and comfort over sporty driving dynamics. Compared to the 730i and 733i, the 728 offered similar levels of refinement but with a noticeable performance deficit. Fuel economy was a key advantage of the 728, making it a more practical choice for everyday driving.
Legacy
The BMW 728, while not the most powerful or sought-after variant of the E23 7 Series, played an important role in establishing the model as a benchmark for luxury sedans. The M286 engine proved to be a reliable and durable powerplant, and many examples are still on the road today. The automatic transmission, while not as engaging as a manual, offered a comfortable and convenient driving experience. In the used car market, the 728 represents a relatively affordable way to experience the classic BMW 7 Series, offering a blend of luxury, comfort, and reliability. Its significance lies in being the foundational model that launched a successful lineage of BMW’s flagship sedan.
