The N55, BMW's First Turbocharged Valvetronic Engine

BMW's TwinPower Turbo

People who are more into technical details and less into design should be thrilled to know that the new BMW 5 Series GT incorporates the company's latest powerplant, known as the N55, basically an upgraded version of the N54.

Thanks to the press release obtained by bmwblog, we now know that the straight-six gasoline engine features for the first time turbocharger technology, High Precision Injection and variable Valvetronic valve management.

The new BMW TwinPower Turbo develops 225 kW/306 hp at a speed of 5,800 rpm, maintaining its maximum torque of 400 Newton-metres/295 lb-ft over a wide speed range from 1,200–5,000 rpm. The press release also mentioned that greater fuel economy and better CO2 management are provided.

Apparently, the turbocharging process is based on the same twin-scroll principle used by the BMW Group that implies low exhaust gas counter-pressure at low engine speeds, the double ducts then creating the necessary flow of gas to drive the turbocharger blades even at low engine speeds.

As a quick reminder, the Valvetronic's biggest advantage is the control and adjustment of valve stroke on the intake valves, making the throttle butterfly used in former times superfluous. The technology reduces throttle losses in the charge cycle process to a minimum and optimises engine response since the air mass required to control the combustion process is masterminded in the engine itself and not outside the power unit with the usual “dead” volume, as BMW explains.

Equipped with this upgraded version of the N54, the BMW 535i Gran Turismo is said to be able to accelerate from a standstill to 100 km/h (62 mh) in 6.3 seconds, with a top speed limited to 250 km/h (155 mph). In terms of fuel economy/autonomy, BMW's 535i GT sits at 8.9 liters/100 kilometers or 31.7 mpg, while CO2 ratings climb at 209 grams per kilometer.
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