The BMW Z4 (E85) 3.0si, produced from 2006 to 2008, represents the high-performance variant of the first-generation Z4 roadster following the LCI (Life Cycle Impulse) facelift. Positioned as the flagship model, it offered a significant step up in power and refinement compared to the 2.0i and 2.5i versions. The 3.0si aimed to deliver a more engaging driving experience, appealing to enthusiasts seeking a sporty and luxurious open-top car. It was a key model in BMW’s strategy to compete with rivals like the Porsche Boxster and Mercedes-Benz SLK in the premium roadster segment within the North American market, as well as throughout Europe and Asia.
Technical Specifications
| Brand | BMW |
| Model | Z4 |
| Generation | Z4 (E85 LCI, facelift 2006) |
| Type (Engine) | 3.0si (265 Hp) |
| Start of production | 2006 |
| End of production | 2008 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Roadster |
| Seats | 2 |
| Doors | 2 |
| Fuel consumption (urban) | 13 l/100 km (18.1 US mpg, 21.7 UK mpg) |
| Fuel consumption (extra urban) | 6.5 l/100 km (36.2 US mpg, 43.5 UK mpg) |
| Fuel consumption (combined) | 8.9 l/100 km (26.4 US mpg, 31.7 UK mpg) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.7 sec |
| Acceleration 0 – 62 mph | 5.7 sec |
| Acceleration 0 – 60 mph | 5.4 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Weight-to-power ratio | 5.3 kg/Hp, 190 Hp/tonne |
| Weight-to-torque ratio | 4.4 kg/Nm, 225.8 Nm/tonne |
| Power | 265 Hp @ 6600 rpm |
| Power per litre | 88.5 Hp/l |
| Torque | 315 Nm @ 2500 rpm (232.33 lb.-ft. @ 2500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | N52B30A |
| Engine displacement | 2996 cm3 (182.83 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 85 mm (3.35 in.) |
| Piston Stroke | 88 mm (3.46 in.) |
| Compression ratio | 10.7:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | DOHC |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Kerb Weight | 1395 kg (3075.45 lbs.) |
| Max. weight | 1650 kg (3637.63 lbs.) |
| Max load | 255 kg (562.18 lbs.) |
| Trunk (boot) space – minimum | 300 l (10.59 cu. ft.) |
| Fuel tank capacity | 55 l (14.53 US gal | 12.1 UK gal) |
| Length | 4091 mm (161.06 in.) |
| Width | 1781 mm (70.12 in.) |
| Height | 1268 mm (49.92 in.) |
| Wheelbase | 2495 mm (98.23 in.) |
| Front track | 1473 mm (57.99 in.) |
| Rear (Back) track | 1523 mm (59.96 in.) |
| Minimum turning circle | 9.8 m (32.15 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Drive wheel | Rear wheel drive |
| Number of gears | 6 gears, manual transmission |
| Front suspension | Spring Strut |
| Rear suspension | Coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 225/45 R17 |
| Wheel rims size | 8J x 17 |
INTRODUCTION
The E85 Z4 3.0si, introduced with the 2006 facelift, represented a significant upgrade over the earlier Z4 models. The LCI brought revised styling, including new headlights and taillights, along with interior enhancements. However, the most substantial change was the introduction of the N52 engine family, specifically the N52B30A in the 3.0si. This engine delivered a substantial power increase, transforming the Z4 into a genuine sports car contender. The 3.0si sat at the top of the Z4 range, offering a more premium experience than the 2.0i and 2.5i models, and served as BMW’s answer to the growing popularity of roadsters from Porsche and Mercedes-Benz.
Powertrain & Engine Architecture
The heart of the 3.0si is the N52B30A, a 3.0-liter inline-six engine. This engine is a naturally aspirated powerplant featuring double overhead camshafts (DOHC) and four valves per cylinder. It utilizes a multi-port fuel injection system, delivering precise fuel metering for optimal performance and efficiency. The N52 engine is renowned for its smooth power delivery and responsive throttle. The engine produces 265 horsepower at 6600 rpm and 232 lb-ft of torque at 2500 rpm. The 3.0si was exclusively offered with a six-speed manual transmission, providing drivers with full control over the engine’s power. The transmission features a precise shift feel and well-chosen gear ratios, enhancing the driving experience.
Driving Characteristics
The 3.0si delivers a noticeably more engaging driving experience than its lower-powered siblings. The increased horsepower and torque translate into quicker acceleration – 0 to 60 mph in approximately 5.4 seconds – and a higher top speed of 155 mph. The manual transmission allows for precise gear selection, maximizing the engine’s performance. The chassis is well-balanced, providing confident handling and a sporty feel. The steering is precise and communicative, offering good feedback to the driver. Compared to the 2.5i, the 3.0si feels significantly more powerful and responsive, while the manual transmission provides a more direct connection to the engine than the optional automatic available on the lower trims.
Equipment & Trim Levels
The 3.0si came standard with a generous array of features, reflecting its position as the range-topping model. Standard equipment included leather upholstery, power-adjustable seats, automatic climate control, a premium sound system, and 17-inch alloy wheels. Optional extras included sport seats, a navigation system, and a premium sound upgrade. The interior design was focused on providing a comfortable and sporty environment for the driver and passenger. The dashboard layout was clean and functional, with easy-to-read gauges and intuitive controls.
Chassis & Braking
The Z4 3.0si features a MacPherson strut front suspension and a multi-link rear suspension, providing a good balance of ride comfort and handling performance. The suspension is tuned to provide a sporty feel without being overly harsh. The braking system consists of ventilated disc brakes on all four wheels, providing ample stopping power. Anti-lock brakes (ABS) are standard, enhancing safety and control. The chassis is relatively lightweight, contributing to the car’s agile handling characteristics.
Market Reception & Comparison
The Z4 3.0si was generally well-received by automotive critics. Reviewers praised its powerful engine, responsive handling, and sporty driving experience. It was often compared favorably to the Porsche Boxster and Mercedes-Benz SLK, with many reviewers noting that it offered a compelling combination of performance, luxury, and value. Fuel economy was respectable for a sports car, averaging around 26 mpg in combined driving. Reliability was generally good, although some owners have reported issues with the cooling system and oil leaks. Compared to the 2.5i, the 3.0si commanded a higher price but offered a significantly more rewarding driving experience.
Legacy
The E85 Z4 3.0si remains a popular choice among enthusiasts today. The N52 engine is known for its reliability and relatively low maintenance costs. While not as technologically advanced as some modern sports cars, the 3.0si offers a pure and engaging driving experience that is highly valued by enthusiasts. The car’s classic roadster styling and strong performance have ensured its continued appeal in the used car market. Parts availability is generally good, making it a relatively easy car to maintain and repair. The 3.0si represents a sweet spot in the Z4 lineup, offering a compelling blend of performance, luxury, and affordability.
