Working with BMW, BorgWarner combined two advanced turbocharging technologies—regulated two-stage (R2S) and variable turbine geometry (VTG)— to accelerate BMW’s engine downsizing strategy without compromising power and torque. The combined system is applied in the new 740d, equipped with a 3.0L straight-six diesel offering up to 4% better fuel economy than its predecessor.
BorgWarner’s R2S turbocharging system consists of two series-connected turbochargers. By applying BorgWarner’s VTG technology to the smaller turbocharger, the engine responds spontaneously at low engine speeds for instant acceleration.
As the engine reaches mid-range speeds, the larger low-pressure turbocharger takes over, providing the boost pressure to reach the maximum engine torque of 600 N·m at 1,500 rpm and a top output of 225 kW/306 horsepower at 4,400 rpm. The combination of technologies achieves both high torque at very low revs and maximum output at high engine speeds while reducing fuel consumption and emissions to a lower level.
The 740d accelerates from 0 to 62 mph (100 km/h) in 6.3 seconds, with combined cycle fuel consumption of 6.9L/100km (34 mpg US) and Euro 5 emissions compliance.
BMW was the first to introduce BorgWarner’s R2S technology in a diesel passenger car. We are pleased to continue our long-standing relationship with BMW with the introduction of our latest advancement.
—Roger Wood, Executive Vice President, BorgWarner