MINI Clubman: In Depth

Press Release

Engines and engineering

The new MINI Clubman is entering the market with a choice of three engines: VALVETRONIC-inspired 1.6-litre petrol in the MINI Cooper, 1.6-litre turbocharged diesel in the Cooper D and 1.6-litre twin-scrolled turbocharged petrol in the Cooper S. In all cases, the car’s performance figures differ only marginally from the Hatch, proving that the MINI Clubman has lost none of the MINI’s revered driving dynamics even with added practicality and approximately 85kg extra weight.

MINI Cooper S Clubman

Powered by a 1.6-litre four-cylinder petrol engine with direct injection and a twin-scroll turbocharger complete with intercooler.

*260Nm with Overboost

More engine highlights:

• Intake camshaft features infinite phase adjustment that balances valve timing to required power
• Common rail direct injection system is pressurised by a high pressure pump at the rear of the intake camshaft
• Fuel from the common rail is pumped into the combustion chambers through the injection valves in the side of the cylinder heads at the exact time and in the exact amount required
• The pistons are cooled by splash oil during the process that works under an extremely high compression ratio of 10.5:1

The twin-scroll turbo-charging system allows a spontaneous build-up of power as the ducts of each pair of cylinders are separated from each other in the exhaust manifold. This helps reduce exhaust gas backpressure at low engine speeds, produces more efficient use of the movement of gas through the manifold and, subsequently, makes the turbocharger’s response more immediate as its rotor blades develop optimum momentum virtually from start-up.

With a wastegate limiting charge pressure to just 0.8 bar at only 1,400 rpm, turbo lag is virtually eradicated. The system contributes to a specific output of almost 110hp per litre.

MINI Cooper Clubman

The 1.6-litre four-cylinder, naturally-aspirated engine features fully variable valve management based on BMW Group’s VALVETRONIC technology. This improves the engine’s response and refinement, as well as the all-round efficiency of the power unit.

It works by adjusting the intake valve lift and opening times within fractions of a second to meet the immediate power and performance requirements of the driver. The big advantage is that it replaces the conventional throttle butterfly on “normal” engines to instantly translate any movement of the throttle pedal directly into engine speed. Intake valve lift is varied infinitely between 0.2 and 9.5 millimetres.

In addition to variable control of valve lift on the intake, valve timing is also controlled on the outlet stroke. This enhances the torque curve to deliver not only high torque at low engine speeds, but also high power at high speeds.

Other key highlights:

• Distance between cylinders: 84mm
• Bore: 77mm
• Stroke: 85.8mm
• Displacement: 1,598cc
• Cylinder block and bearing housing of aluminium alloy
• Two-piece bedplate crankcase construction derived from technology developed in BMW Group’s motor sport development programmes
• Camshafts of composite structure; camrings of high-strength stainless steel are shrunk-fit to the camshaft then fine-polished to an accuracy of 1/1000th of a millimetre
• Alternator and climate compressor driven by one single poly-V-belt contribute to making the new MINI engine one of the smallest four-cylinders in production
• Volume-flow-controlled oil pump is chain driven and, as with the water pump, is driven by demand rather than offering a constant flow. Both systems contribute to an improvement in fuel consumption

MINI Cooper D Clubman

Four-cylinder turbo diesel with common-rail fuel injection and variable turbine geometry ensures optimum smoothness, efficiency and response even at low speeds. A diesel particulate filter almost eliminates diesel exhaust emissions and helps to make the MINI diesel engine one of the most environmentally friendly cars available.

Under normal conditions peak torque of 240Nm is achieved between 1,750 and 2,000rpm. A substantial 70 per cent of the engine’s maximum torque is available at speeds of just 1,250 rpm, meaning the new Cooper D has exhilarating pulling force even at low engine speeds. Deploying the engine’s Overboost function briefly gives the Cooper D an additional 20Nm of torque, meaning the driver will experience 260Nm at 2,000rpm. MINI enthusiasts will recognise this torque figure is identical to that produced by the new MINI Cooper S.

*260Nm with Overboost

Further highlights of the new engine:

• Second-generation common rail diesel technology operating at a maximum pressure of 1,600 bar is key to the new diesel engine’s combustion process.
• Additionally, refinement is achieved using a precise multiple-injection process for each operating cycle.
• The six intake ducts in the new injectors are only 0.135mm in diameter, while the combustion chambers have been optimised in their shape and dimensions to prevent unwanted turbulence and maintain a smooth and consistent combustion process at all times.

As with all MINI Hatch models, the MINI Clubman range benefits from the improvements introduced in production from August 2007 to bring further reductions in fuel consumption and emissions.

Technologies include Brake Energy Regeneration, Auto Start-Stop function and a Gearshift Point Indicator.

Brake Energy Regeneration

This technology ensures that the output from the engine is converted primarily into drive power, with electricity being generated for the on-board network only when the engine is on overrun or during application of the brakes. To achieve this effect the alter­nator is automatically disengaged from the engine while under power. Accordingly, the power the alternator would consume in the conventional mode now remains fully available for even faster and more dynamic acceleration.

An adequate supply of electrical energy to the on-board system is nevertheless ensured at all times, since the alternator is activated again as soon as the MINI returns to overrun or the driver applies the brakes.

Auto Start-Stop

The new Auto Start-Stop function on all manual gearbox versions of the MINI Clubman serves to effectively reduce fuel consumption and emissions while the car is standing still. Whenever the car comes to a stop (e.g. traffic lights), Auto Start-Stop automatically switches off the engine as soon as the driver shifts to neutral and takes his foot off the clutch pedal. To re-start the engine, the driver presses down on the clutch pedal again, and the engine re-starts automatically and immediately. The driver may deactivate the system if he chooses. The system will not activate if the engine oil is still cold, the battery power is low or the outside temperature is less than three degrees Celsius.

Auto Start-Stop serves to optimise fuel efficiency in city traffic. The consumption of energy and the generation of exhaust emissions is reduced to zero in a very simple and straightforward process every time the car comes to a stop.

Gearshift Point Indicator

The driver of a manual gearbox MINI Clubman is able to focus on the most efficient style of motoring because the ideal ‘economy’ gear is shown by a numeric symbol in the cockpit display beneath the rev counter. The electronic engine ‘brain’ analyses engine speed, driving conditions and the position of the accelerator pedal to calculate the most efficient style of motoring and suggests the respective gear to the driver.

Transmission

The key to MINI’s great driving is the direct response between driver inputs and reactions on the road, and the transmission is the defining touch.

The MINI Cooper and Cooper D Clubman come as standard with a six-speed manual. A single-cone syncromesh, carbon friction plates on the first two gears, a helical gear pattern and syncromesh on reverse are all features that remove noise and refine shifts.

The Cooper S’ six-speed manual provides a double cone that synchronises first and second to shorten the shift times and makes changing rapidly from first to second even easier.

The six-speed automatic transmission maintains the ideal balance of power and torque and is available for all three engine variants. The shift-paddles ensure that if the driver really is a driver, he or she never need lose touch with the chunky new steering wheel. The sporty DS mode has noticeably shorter gear-change times.

An automatic MINI can, of course, simply be left in Drive to allow the car to make the best possible gear selections for the road ahead, or gears can be changed manually by pushing forward or pulling back the gear selector for a downshift or to go up the ‘box