The engine's peak torque of 240 Nm or 177 lb-ft is maintained consistently between 1,600 and 5,000 rpm. When accelerating, torque is even boosted briefly to 260 Nm or 192 lb-ft by a short increase in turbocharger pressure. Referred to as "Overboost", this function gives the MINI Cooper S even more dynamic acceleration, acting exclusively on the engine's torque, not on maximum output. The four valves per cylinder are controlled by two overhead camshafts, friction-optimised roller arms, and hydraulic valve clearance compensation units. The exhaust valves are filled with sodium in order to meet the greater cooling requirements of a turbocharged power unit. The intake camshaft comes with infinite phase adjustment setting the valve timing to the driver's current power and performance requirements. On the road, this means optimum power and torque combined with superior fuel economy and emission management.

Fuel is injected into the turbocharged four-cylinder by means of common-rail direct gasoline injection: The stainless-steel common rail delivering fuel to all cylinders is filled with fuel under high pressure by a high-pressure pump at the rear end of the intake camshaft. Injection valves positioned at the side on the cylinder head deliver fuel from the common rail directly to the combustion chambers with exact dosage within fractions of a second. Four valve pockets and the combustion chamber trough in the middle of each piston ensure optimum stratification of the homogeneous fuel/air mixture, consistently maintaining a lambda factor of 1.0. Running in cast-iron bushes and subjected to high thermal loads also on account of the compression ratio of 10.5:1 relatively high for a turbocharged power unit, the pistons themselves are cooled by splash oil lubrication.

Featuring a twin-scroll turbocharger, the new MINI Cooper S is introducing a new technology in its segment in the interest of particularly dynamic and spontaneous power and performance: "Twin-scroll" means that the ducts in the exhaust manifold and the turbocharger are separated from one another in each case for two cylinders. Reducing exhaust gas counterpressure at low speeds, this enables the engine to capitalise on the dynamic action of the gas columns pulsating within the manifold. The result is even better response by the turbocharger, with its blades building up optimum momentum right from the start at lower engine speeds.

Charge pressure limited by a wastegate to 0.8 bar starts to build up from an engine speed of just 1,400 rpm, virtually eliminating the "turbo gap" so typical of a conventional turbocharged engine but hardly to be felt at all when accelerating in the new MINI Cooper S. Indeed, the 1.6-litre turbocharged power unit shows the kind of response you would normally only expect in a much larger normally aspirated engine: "The principle to get the same kind of power and performance out of a smaller and more efficient engine, enjoying all the advantages of a large engine, is referred to as 'downsizing'", states Drivetrain Project Manager Erich Sonntag. "And developing output per litre of approximately 110 horsepower, the turbocharged power unit of the new MINI is a particularly good example of this principle."

The flow of exhaust gas rushing by accelerates the turbine wheel to a speed of up to 220,000 rpm. The compressor wheel running on the same shaft, in turn, compresses intake air at the same time. To increase the supply of fresh air to the cylinders - cold air contains a larger share of oxygen - the intake air compressed by the turbocharger flows through intercoolers before reaching the combustion chamber.

The technology for cooling the turbocharger is equally sophisticated in technical terms, with the twin-scroll turbocharger in the new MINI being maintained within the optimum temperature range by a combination of oil and water cooling. An electrical auxiliary pump maintains the coolant circulation process for some time after the engine itself has been switched off in order to avoid the risk of excessive heat building up in the turbocharger subject to extremely high thermal loads.



Six Speeds on All Models

Manual and Automatic Transmission on the new MINI

Both engine versions of the new MINI come as standard with a six-speed manual gearbox. The optional automatic transmission available in each case also features six speeds controlled by five clutches to provide an absolutely smooth and consistent gearshift virtually without the slightest interruption of traction and pulling power.

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