The BMW 730d Steptronic, introduced as part of the E38 7 Series facelift in 1998, represented a significant step for BMW into the luxury diesel market. Produced through 2000, this variant offered a blend of refinement, performance, and fuel efficiency that appealed to European buyers, particularly those covering long distances. Positioned as the entry-level diesel offering in the E38 range, it sat below the more powerful 740d and provided a more economical alternative to the gasoline-powered 7 Series models. The 730d aimed to deliver the flagship experience of the E38, but with a focus on reduced running costs.
Technical Specifications
| Brand | BMW |
| Model | 7 Series |
| Generation | 7 Series (E38, facelift 1998) |
| Type (Engine) | 730d (184 Hp) Steptronic |
| Start of production | 1998 |
| End of production | 2000 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 12.1 l/100 km (19.4 US mpg, 23.3 UK mpg, 8.3 km/l) |
| Fuel consumption (extra urban) | 6.8 l/100 km (34.6 US mpg, 41.5 UK mpg, 14.7 km/l) |
| Fuel consumption (combined) | 8.8 l/100 km (26.7 US mpg, 32.1 UK mpg, 11.4 km/l) |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 9.2 sec |
| Acceleration 0 – 62 mph | 9.2 sec |
| Acceleration 0 – 60 mph | 8.7 sec |
| Maximum speed | 220 km/h (136.7 mph) |
| Weight-to-power ratio | 9.9 kg/Hp, 100.5 Hp/tonne |
| Weight-to-torque ratio | 4.5 kg/Nm, 224 Nm/tonne |
| Power | 184 Hp @ 4000 rpm |
| Power per litre | 62.9 Hp/l |
| Torque | 410 Nm @ 2000 rpm (302.4 lb.-ft. @ 2000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M57D30 |
| Engine displacement | 2926 cm3 (178.56 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 84 mm (3.31 in.) |
| Piston Stroke | 88 mm (3.46 in.) |
| Compression ratio | 18:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 7 l (7.4 US qt | 6.16 UK qt) |
| Coolant | 9.2 l (9.72 US qt | 8.09 UK qt) |
| Kerb Weight | 1830 kg (4034.46 lbs.) |
| Max. weight | 2365 kg (5213.93 lbs.) |
| Max load | 535 kg (1179.47 lbs.) |
| Trunk (boot) space – minimum | 500 l (17.66 cu. ft.) |
| Fuel tank capacity | 85 l (22.45 US gal | 18.7 UK gal) |
| Length | 4984 mm (196.22 in.) |
| Width | 1862 mm (73.31 in.) |
| Height | 1435 mm (56.5 in.) |
| Wheelbase | 2930 mm (115.35 in.) |
| Front track | 1552 mm (61.1 in.) |
| Rear (Back) track | 1568 mm (61.73 in.) |
| Drag coefficient (Cd) | 0.30 |
| Minimum turning circle | 11.6 m (38.06 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 5 gears, automatic transmission Steptronic |
| Front suspension | Wishbone |
| Rear suspension | Inclined Lever |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | 215/65 R16 |
| Wheel rims size | 16 |
Powertrain & Engine Architecture
The heart of the 730d Steptronic was the M57D30, a 2.9-liter inline-six diesel engine. This engine was a key component of BMW’s second-generation common rail diesel technology. The M57D30 featured a turbocharger with an intercooler, boosting power output to 184 horsepower at 4000 rpm and a substantial 410 Nm (302 lb-ft) of torque at just 2000 rpm. The common rail direct injection system, operating at a high pressure of 1,350 bar, allowed for precise fuel metering and optimized combustion. The engine also incorporated four valves per cylinder and a robust cast iron block. The “Steptronic” transmission was BMW’s name for its 5-speed automatic gearbox, offering both fully automatic operation and a manual shift mode for greater driver control. This transmission was specifically tuned to work with the diesel engine’s torque characteristics, providing smooth shifts and efficient power delivery.
Driving Characteristics
The 730d Steptronic offered a distinctly different driving experience compared to its gasoline-powered siblings and even the higher-output 740d. While not as overtly sporty as the 740i, the 730d provided ample power for comfortable and confident cruising. The high torque output meant strong acceleration from low speeds, making it well-suited for overtaking maneuvers. The Steptronic transmission, while smooth, wasn’t as quick to respond as some later iterations, and the 0-60 mph time of around 8.7 seconds reflected this. Compared to a manual transmission equipped 730d, the automatic offered convenience but sacrificed some responsiveness. The focus was on relaxed, effortless progress, rather than outright performance. The weight distribution, typical of a front-engine, rear-wheel-drive sedan, contributed to balanced handling, though the car’s considerable weight (around 4,034 lbs) was noticeable in tighter corners.
Equipment & Trim Levels
The 730d Steptronic came standard with a generous array of luxury features, befitting its flagship status. These included leather upholstery, power-adjustable front seats with memory function, automatic climate control, a premium sound system, and wood trim throughout the cabin. Standard safety equipment included ABS, traction control, and a driver and passenger airbag system. Optional extras were plentiful, allowing buyers to personalize their vehicles. These included features like a navigation system, upgraded sound systems, rear seat entertainment, parking sensors, and a sunroof. The interior design was typical of the E38, emphasizing understated elegance and high-quality materials.
Chassis & Braking
The E38 7 Series featured a sophisticated chassis designed for both comfort and handling. The front suspension utilized a double-wishbone setup, while the rear employed an inclined lever system. This configuration provided a smooth ride and good control. The 730d Steptronic was equipped with ventilated disc brakes at the front and solid discs at the rear. ABS (Anti-lock Braking System) was standard, enhancing braking performance and stability. The steering was a hydraulic power-assisted rack and pinion system, offering precise and responsive control. The suspension was tuned to prioritize comfort, but still provided a reasonably controlled driving experience.
Market Reception & Comparison
The 730d Steptronic was generally well-received by automotive critics, particularly in Europe where diesel engines were more popular. It was praised for its fuel efficiency, smooth ride, and refined interior. However, some critics noted that the performance wasn’t as exhilarating as the gasoline-powered models. Compared to the 740d, the 730d offered a more affordable entry point into the E38 range, but with a noticeable reduction in power and performance. Fuel economy was a key advantage, with the 730d achieving around 26.7 US mpg in combined driving, significantly better than the gasoline alternatives. Reliability was generally good, although the complex common rail diesel injection system could be prone to issues if not properly maintained.
Legacy
The BMW 730d Steptronic played a crucial role in establishing BMW as a leader in the luxury diesel market. The M57D30 engine proved to be a durable and reliable powerplant, and many examples are still on the road today. In the used car market, the E38 730d represents a relatively affordable way to experience the luxury and refinement of the E38 generation. While maintenance costs can be higher than for gasoline-powered models due to the complexity of the diesel injection system, the 730d remains a popular choice for those seeking a comfortable, efficient, and well-equipped luxury sedan. Its introduction paved the way for future generations of BMW diesel models, solidifying the brand’s commitment to diesel technology.
