Engine partners BMW Group and PSA Peugeot Citroën have introduced a new, naturally aspirated 1.4 liter gasoline engine as part of a growing family. This new engine, which is applied in the upcoming new MINI One (earlier post) is directly derived from the existing 1.6 liter engine already applied in the MINI Cooper and Cooper S as well as on the Peugeot 207.
The new engine delivers 71 kW (95 hp) of power at 6,000 rpm. The torque varies from 136 Nm to 140 Nm depending on the application. It uses intake and exhaust variable valve timing and variable valve lift to optimize the output, while decreasing fuel consumption.
The variable valve lift system on the inlet valves allows the maximum valve lift to be adjusted gradually according to the position of the accelerator pedal. This technology removes the need for a throttle butterfly as the engine power is now controlled through the infinite adjustment of the inlet valve lift and intake valve opening times.
In a conventional engine the engine power output is controlled by means of a throttle butterfly. The required amount of air to be drawn into the engine is regulated by the position of the throttle butterfly; however, at certain engine speeds and throttle butterfly positions, the incoming air has to squeeze past the partially closed or closed butterfly, reducing the air flow into the engine.
Overcoming this resistance reduces potential power and overall engine efficiency and also increases fuel consumption.
The combination of the variable valve timing (VVT) system and the variable inlet valve lift system improves the engine’s efficiency and reduces fuel consumption. It also delivers improved engine responsiveness and greater engine flexibility.
The new engine has the same bore as its parent, but a reduced stroke.
As applied in the new MINI One, the 1.4-liter engine offers fuel consumption of 5.7 l/100km (41.3 mpg US), compared to 6.8 l/100km (35 mpg US) from its predecessor—a 16% reduction in fuel consumption. CO2 emissions are now 138 g/km, compared to 164 g/km produced by the previous model.
The companies plan full production of this engine family (1.4-liter and 1.6-liter) to reach one million units per year. The companies envision that of that, 40% will be the naturally aspirated 1.4-liter unit, 40% the naturally-aspirated 1.6-liter unit, and 20% will be a 1.6-liter turbocharged gasoline direct injection unit.
The PSA Peugeot Citroën plant of Douvrin (region Nord Pas de Calais) will manufacture all the engine’s components for both companies, and is also in charge of the engine assembly for PSA Peugeot Citroën. BMW will assemble the engines for MINI in its plant in Hams Hall (UK).
BMW Group and PSA Peugeot Citroën announced their partnership in Munich in December 2004. The joint development of the engines took place in the BMW Group R&D Centre in Munich with teams of engineers of both groups. R&D costs are shared by both partners.