BMW 3-Series Coupé revealed

First turbocharged BMW not just saloon clone

BMW’s new 3-Series Coupé range goes on sale in the UK on 23 September 2006. The third generation of compact coupé marks the introduction of the first ever twin-turbo petrol-powered engine in a production BMW as well as pioneering Direct Injection technology. Two models will be available at launch.

As with the 5- and 6-Series relationship, BMW said it's keen to differentiate the coupé from its four-door sibling -- and be able to charge more for it. From the front, side and rear, the car is clearly related to the rest of the series but looks more elongated.

Key highlights in exterior design are the kidney grilles and restyled headlamps and, at the rear, the broad rear lights use horizontal light rods with bright LED illumination. Another change from the other models in the 3-Series range is the use of lightweight materials in the body construction in the coupé. While all 3 Series models use tailored blanks that increase panel thickness where structural rigidity is needed, and reduce thickness where it’s not, the coupé also uses plastics in its construction. As a result, the coupé's front wings weigh some 10Kg less than the saloon's.

Twin-turbo in-line six-cylinder

**BMW 3-Series Coupe**
Model	OTR Price	Power (hp)	Torque(lb-ft)	Acceleration (0 – 62mph)	Top speed (mph)	Combined cons. (mpg)
BMW 325i SE Coupé	£28,090	218	184	6.9	153	33.6
BMW 335i SE Coupé	£33,420	306	295	5.5	155	29.7

The BMW 335i SE accelerates from zero to 62mph in 5.5 seconds, and has an electronically-limited top speed of 155mph -- it's the fastest 3-Series car, said BMW. This level of performance comes from a pair of turbochargers, each supplying compressed air to three cylinders each. The use of two smaller units ensures that the turbochargers react more quickly to changes in the throttle position all the way to the 7,000rpm red line while also eliminating turbo lag.

Turbocharging means the engine is also considerably lighter than a normally aspirated powerplant of equal power -- 70Kg less than an eight-cylinder engine of corresponding performance in the case of the 335i -- benefiting both fuel economy and weight distribution.

BMW’s all new high-precision direct injection system also aids these high levels of performance while also benefiting economy. Piezo injectors, located centrally in the combustion chamber between the inlet and exhaust valves, deliver atomised fuel in a conical burst into the chamber to ensure a smooth, efficient burn.

Piezo crystal injectors work when an electrical current is passed through the crystal to create a very precise and consistent fuel delivery. The result? Only the exact volume of fuel required is delivered into the combustion chamber on each cycle guaranteeing that all the vaporised mixture is burnt. This method of injection also serves to aid combustion chamber cooling, thus offering a higher compression ratio. As a consequence, the new car delivers an average fuel consumption of 29.7mpg on the combined cycle.

Entry-level six-cylinder

At the launch in September, the new 325i SE Coupé will form the entry point to the range. Delivering 218hp and 250Nm of torque from its 2.5-litre in-line six-cylinder engine, zero to 62mph is achieved in 6.9 seconds and the top speed is 153mph, with 33.6mpg on the combined cycle.

This level of economy is also made possible as a result of a number of weight and power saving measures in the engine. The 325i Coupé is the latest BMW to benefit from the magnesium-aluminium composite cylinder block first seen on the BMW 630i in spring 2004. The lightweight combination of materials reduces the overall mass of the car and helps achieve the near-perfect 50:50 front-to-rear weight distribution for improved handling.

Finally, the 2.5-litre engine uses an electrically-powered water pump. This not only eliminates the engine power normally needed to drive a conventional crankshaft driven unit but also reduces the engine heat-up time to improve engine efficiency and occupant comfort.

Gearbox options

All new BMW 3 Series Coupé models come with a close ratio six-speed manual gearbox as standard. The automatic gearbox option uses an innovative torque converter and software set up, said BMW, offering a 40 per cent improvement in response time to throttle inputs and a gear-shift time nearly half that of a conventional automatic transmission. Whenever a driver wants to take control of gear changes a pair of selection paddles located behind the steering wheel can be used to change gears.

Suspension and steering

A double-joint tie bar front axle with spring struts made almost entirely from aluminium and a five-link rear axle work in combination with a rigid body structure for stability and comfort. The coupé also comes as standard with Dynamic Stability Control+which includes comfort and safety systems such as brake pads that are dried in wet weather conditions and brakes that are applied harder when any possible brake fade is detected.

Rack and pinion steering is standard or you can opt for the active steering system that varies the steering ratio as a proportion of road speed. The system additionally links into the DSC+ system, adding small amounts of steering correction without driver input when oversteer is detected.

Safety systems

All of the passive safety systems of the new Coupé are controlled by a restraint and support system. The six standard airbags, seatbelt pre-tensioners and belt force limiters are all activated by the type and severity of a collision. Xenon headlights are standard, or you can opt for adaptive headlights that aim in the direction the car is travelling rather than the direction it is pointing.

Drivers behind might also notice BMW’s Brake Force Display at work. When the driver of the coupé needs to execute an emergency stop, or when the ABS system is in operation, the driver behind is warned of the danger ahead by an additional illumination of the LED brake lights in the lamp cluster.

Interior

The seatbelt is now delivered to the driver courtesy of a feeder arm integrated into the B-pillar. This only operates on the passenger side when the airbag’s seat detector recognises an occupant. Both driver and passenger in the 3-Series Coupé sit lower in the car than in the saloon. The coupé provides up to 440 litres of boot space.

Future coupés

Other engine derivatives start production in September to broaden the 3 Series Coupé range. The new BMW 330i Coupé will develop 272hp from its normally-aspirated 3.0-litre six cylinder engine that, like the smaller engined 325i Coupé, uses magnesium alloy in its engine construction. Acceleration to 62mph is dispatched from standstill in 6.1 seconds with an electronically limited top speed of 155mph. The 330i Coupé still delivers 32.1mpg on the combined cycle.

At the same time as the 330i, the new BMW 330d Coupé will start production, offering 231hp and 369lb-ft of torque. Performance and economy are both top priorities for the diesel-powered coupé, with the car posting a zero to 62mph time of 6.6 seconds while still delivering 43.5mpg on the combined cycle.

Details of the future entry-point BMW 320i and 320d Coupé models will be announced at a later date.

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