BorgWarner says that a new four-cylinder diesel generation from Mercedes-Benz meets the Euro 5 standard and achieves 20% more power output with 13% less fuel.
The firm says that the the use of regulated two-stage turbocharging from BorgWarner Turbo & Emissions Systems is important to that performance result.
The new power unit will be installed in various vehicle series and will form the backbone of Mercedes-Benz diesel engine production, it says.
The engine is designed for either transverse or longitudinal installation and is equally suitable for all-wheel-drive vehicles. To begin with, three versions are planned for use in passenger cars: the 200 CDI, 220 CDI and 250 CDI. With the application of R2S technology in the 220 CDI and 250 CDI, Mercedes-Benz is implementing two-stage turbocharging for the first time in a series-production passenger car diesel engine, following its use in the previous engine generation in the Sprinter van
The turbocharging system allows continuously variable adaptation of the turbine and compressor sides of the system for each engine operating point. The advantage of R2S over a single-stage process is that it increases the engine’s rated output while at the same time improving torque delivery at low revs, thus enhancing the diesel engine’s acceleration characteristics with its rapid build-up of boost pressure.

As a result, BorgWarner says, R2S resolves the conflict of objectives between achieving a high torque at very low revs and providing maximum output at high engine speeds.