The BMW 3 Series Sedan (E30) 324td Automatic, produced from 1987 to 1991, represents a unique offering within the popular E30 generation. Positioned as a fuel-efficient and torquey alternative to the gasoline-powered models, the 324td combined a turbocharged diesel engine with a four-speed automatic transmission. This variant was primarily aimed at European markets where diesel engines were favored for their economy and durability, offering a comfortable and practical grand touring experience. It occupied a middle ground in the 3 Series lineup, offering more refinement than the base models but lacking the outright performance of the 325i or M3.
Technical Specifications
| Brand | BMW |
| Model | 3 Series |
| Generation | 3 Series Sedan (E30, facelift 1987) |
| Type (Engine) | 324td (115 Hp) Automatic |
| Start of production | 1987 |
| End of production | 1991 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 8.9 l/100 km (26.4 US mpg, 31.7 UK mpg, 11.2 km/l) |
| Fuel consumption (extra urban) | 5.2 l/100 km (45.2 US mpg, 54.3 UK mpg, 19.2 km/l) |
| Fuel consumption (combined) | 6.9 l/100 km (34.1 US mpg, 40.9 UK mpg, 14.5 km/l) |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 12.8 sec |
| Acceleration 0 – 62 mph | 12.8 sec |
| Acceleration 0 – 60 mph | 12.2 sec |
| Maximum speed | 182 km/h (113.09 mph) |
| Weight-to-power ratio | 11 kg/Hp, 91.3 Hp/tonne |
| Weight-to-torque ratio | 5.7 kg/Nm, 176.2 Nm/tonne |
| Power | 115 Hp @ 4800 rpm |
| Power per litre | 47.1 Hp/l |
| Torque | 222 Nm @ 2400 rpm (163.74 lb.-ft. @ 2400 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M21D24 |
| Engine displacement | 2443 cm3 (149.08 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 80 mm (3.15 in.) |
| Piston Stroke | 81 mm (3.19 in.) |
| Compression ratio | 22:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Precombustion chamber injection |
| Engine aspiration | Turbocharger |
| Engine oil capacity | 5.5 l (5.81 US qt | 4.84 UK qt) |
| Coolant capacity | 12 l (12.68 US qt | 10.56 UK qt) |
| Kerb Weight | 1260 kg (2777.82 lbs.) |
| Max. weight | 1720 kg (3791.95 lbs.) |
| Max load | 460 kg (1014.13 lbs.) |
| Trunk (boot) space – minimum | 425 l (15.01 cu. ft.) |
| Fuel tank capacity | 55 l (14.53 US gal | 12.1 UK gal) |
| Length | 4325 mm (170.28 in.) |
| Width | 1645 mm (64.76 in.) |
| Height | 1380 mm (54.33 in.) |
| Wheelbase | 2570 mm (101.18 in.) |
| Front track | 1405 mm (55.31 in.) |
| Rear (Back) track | 1415 mm (55.71 in.) |
| Drivetrain Architecture | Rear wheel drive |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, automatic transmission |
| Front suspension | Coil spring |
| Rear suspension | Coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Drum |
| Assisting systems | ABS (Anti-lock braking system), Hydraulic Steering |
| Tires size | 195/65 HR14 |
| Wheel rims size | 14 |
Powertrain & Engine Architecture
The heart of the 324td Automatic is the BMW M21D24 engine, a 2.4-liter inline-six cylinder diesel. This engine utilizes precombustion chamber injection, a system where fuel is injected into a small pre-chamber connected to the main combustion chamber, promoting more complete combustion and reducing engine noise. A turbocharger, a Garrett unit in most applications, significantly boosts power output compared to naturally aspirated diesel engines of the time. The M21 engine is known for its robust construction and longevity. The four-speed automatic transmission, a ZF 4HP22 unit, was chosen for its smoothness and ease of use, catering to drivers prioritizing comfort over sporty engagement. This transmission features hydraulic control and a torque converter, providing smooth shifts but at the expense of some efficiency compared to a manual gearbox.
Driving Characteristics
The 324td Automatic delivers a distinctly different driving experience compared to its gasoline counterparts. While lacking the high-revving eagerness of the 325i, it offers a substantial amount of low-end torque, making it effortless to drive in everyday situations. The automatic transmission, while smooth, does slightly dull the engine’s responsiveness. Acceleration to 60 mph takes around 12.2 seconds, and top speed is around 113 mph. The gear ratios are optimized for fuel economy and relaxed cruising, rather than outright performance. Compared to the manual transmission version of the 324td, the automatic sacrifices some acceleration and responsiveness, but gains in convenience and ease of driving.
Equipment & Trim Levels
The 324td Automatic typically came equipped with a reasonable level of standard features, including power steering, central locking, and a basic stereo system. Interior upholstery was usually cloth, with options for leather available at extra cost. Trim levels varied depending on the market, but generally included features like electric windows, sunroof, and upgraded sound systems. The dashboard layout was typical of the E30, with a functional and straightforward design. Optional extras included air conditioning, heated seats, and a trip computer.
Chassis & Braking
The 324td Automatic utilizes the E30’s well-regarded chassis, featuring independent suspension at all four wheels. The front suspension employs coil springs and MacPherson struts, while the rear utilizes a semi-trailing arm setup with coil springs. The braking system consists of ventilated discs at the front and drum brakes at the rear. ABS (Anti-lock Braking System) was available as an option, enhancing safety. The suspension tuning is geared towards comfort and stability, providing a compliant ride quality. Stabilizer bars were fitted front and rear to reduce body roll during cornering.
Market Reception & Comparison
The 324td Automatic was generally well-received in Europe as a practical and economical alternative to the gasoline-powered 3 Series models. Critics praised its fuel efficiency and comfortable ride, but noted its lack of outright performance. Compared to the 325i, the 324td Automatic offered significantly lower running costs but a less engaging driving experience. Against other diesel-powered competitors, the 324td stood out for its refinement and build quality. Its fuel economy figures of around 34.1 US mpg combined were considered excellent for the time.
Legacy
The BMW E30 324td Automatic has developed a loyal following among enthusiasts, particularly those seeking a classic BMW with good fuel economy and reliability. The M21D24 engine is known for its durability, and well-maintained examples can still provide years of reliable service. While not as sought-after as the 325i or M3, the 324td Automatic offers a unique and appealing combination of comfort, economy, and classic BMW styling. Today, these cars are increasingly collectible, with prices reflecting their rarity and historical significance. Finding parts can sometimes be a challenge, but a strong aftermarket support network exists for the E30 platform.
