General

2.1 General

An enhanced engine generation based on the DFI (direct fuel injection) engines familiar from the previous models is used for the 911 Carrera (991) models. By improving efficiency and using the latest engine technology, it has been possible to bring about a further significant reduction in the fuel consumption values for the 3.4-liter and 3.8-liter engines compared with the previous models.

The focus in this chapter is on the principle new features of the 911 Carrera (991) compared with the previous model (997).

2_401_11 DME engine electronics 2

General Technical data 13 15

DME control unit DME diagnosis Power supply Fuel system Intake system Mixture formation

17 19 22 23 27 32 Ignition system 39 Exhaust system, emission control 40 Auto Start Stop function

46 Coasting function 51 Thermal energy management 53

DME engine electronics 2

2_402_11 Development goals for the engine

The characteristics that are typical of the 911 Carrera, such as superior driving dynamics and performance combined with low fuel consumption, low CO2 emissions and exceptional day-to-day usability, have been further improved.

Increase in engine power

• + 5 hp for the 911 Carrera (3.4-liter) • + 15 hp and + 20 Nm for the 911 Carrera S (3.8-liter)

Reduced fuel consumption and emission values

• Reduced by 8 to 15%, depending on the model. • Fuel consumption and emission values on the 3.4-liter Carrera with Porsche

Doppelkupplung (PDK), for example, have been reduced by 15%. In addition to direct fuel injection (DFI), which was introduced to sports cars with the 911 Carrera (997) and has already allowed improvements in fuel economy compared with the previous models, the new flat-six engines feature the following new technologies: • Thermal management for engine, transmission and heating • Auto Start Stop function • Variable deceleration fuel cutoff • Vehicle electrical system recuperation (- 0.1 liters in NEDC - New European

Driving Cycle) • Displacement downsizing on the 911 Carrera (- 0.2 liters) • Coasting in conjunction with 7-speed Porsche Doppelkupplung (PDK) • 7-speed manual transmission (+ 1 gear) • Electromechanical power steering (- 0.1 liters)

Performance/driving dynamics

• Sport button as standard • Sport Chrono package incl. dynamic engine mountings (optional)

General changes to the DME

The new engines use new 6 hole injectors compared to previous models. These ensure more efficient mixture formation, smoother running and maximum power output.

The flow resistance has been reduced by optimizing the air cleaner and air cleaner housing.