MAHLE Advanced Downsizing Engine

Engine downsizing is now firmly established as a proven approach for delivering significant fuel economy benefits. MAHLE began the development of its first generation downsizing engine in 2007 to demonstrate that high performance levels could still be achieved whilst maintaining the inherent efficiency advantages of a small displacement unit.

Key design features included

  • 3 cylinder, short stroke configuration
  • 1.2 liter displacement
  • Central, spray-guided gasoline direct injection
  • Two-stage turbocharging
  • COSCAST® cylinder head, block, bedplate and all major castings
  • Low friction valve train and power cell
  • Dual independent cam phasing
  • MAHLE NIKASIL® parent bore coating in cylinders
  • Split cooling system (separate head and block circuits) with electric water pump
  • Through-bolting construction

First generation engine with development turbocharger

  • Power output             144 kW / 196 PS
  • Specific power           120 kW / liter
  • Peak torque              286 Nm (30 bar BMEP)
  • Flexibility                  250 Nm @ 1,500 rpm
  • Minimum BSFC         235 g/kWh

All from a compact and lightweight 3-cylinder, all aluminum engine with a

displacement of just 1.2 liters.

For a near-term production feasible solution with similar performance, the second generation downsizing engine was designed with a bespoke, fixed geometry, single turbocharger from Bosch Mahle Turbo Systems (BMTS). The latest multi-hole solenoid fuel injectors with the MED17 engine management system from Bosch were introduced. This engine was further developed on the test bed throughout 2009 and some equally impressive performance figures were achieved, including a power output of >160 bhp and equivalent torque and fuel economy values to the first generation, twin-turbo engine.

Second generation engine with single BMTS turbocharger

  • Power output             120 kW / 163 PS
  • Specific power           100 kW / liter
  • Peak torque               286 Nm (30 bar BMEP)
  • Flexibility                   250 Nm @ 1,500 rpm
  • Minimum BSFC           235 g/kWh

In 2014, work began on a further update to the MAHLE downsizing engine to increase the specific output up to 160 kW/liter through the application of 48V eSupercharging. A fast response supercharger, which provides up to 2 bar boost continuously, allows the engine to produce high torque at low speed and excellent transient response, as well as accommodating a larger conventional turbocharger to deliver  peak power. The latest ‘twin-boosted’ downsizing engine maintains the same fuel efficiency to the previous generation engine within the same operating area, but now delivers significantly higher performance.

Third generation engine with 48V eSupercharger combined with turbocharger

  • Power output               193 kW / 262 PS
  • Specific power             161 kW / liter
  • Peak torque                334.22 Nm (35 bar BMEP)
  • Flexibility                    290 Nm @ 1,500 rpm
  • Minimum BSFC            235 g/kWh

MAHLE eSupercharged Downsizing Engine [PDF; 1902 KB].

Animated View of MAHLE Advanced Downsizing Engine

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