New Peugeot 3-Cylinder Gasoline Engine Family Optimizes Combustion

March 20, 2014

Patrick Ponticel

Peugeot's new Pure Tech triples feature an open-deck cylinder block design. The company claims about 95% of peak torque is available from 1500 to 3500 rpm.

A new family of 3-cylinder gasoline engines from Peugeot, called PureTech, employs optimized combustion to offer what the automaker calls a breakthrough in terms of fuel economy, CO₂, and drivability. The family consists of 1.0- and 1.2-L naturally aspirated units along with 1.2-L turbocharged units—all employing direct injection. There are five units in all, covering a power range from 50 to 96 kW (67 to 129 hp). More than 250 engineers developed the engines over four years. Applications were filed for 121 patents. Major factors in optimized combustion include centrally positioned, high-pressure (200 bar, or 2.9 ksi) injection. Also contributing are the shape of the spray (optimized via improved laser technology for injector manufacture), the management of injection pulses (up to three per combustion event), and the introduction of variable intake and exhaust timing. Since friction accounts for roughly 20% of the power consumed in an engine, Peugeot says, its engineers optimized the size of the crankshaft, offset the cylinders, employed a lubricated timing belt, and applied a diamond-like carbon coating on the piston pins, rings, and push rods. The oil pump is controlled electronically to provide the optimal amount of lubrication. Average fuel-economy improvement of the five PureTech variants is 18% compared to the 1.6-L VTi/THP engine the new ones replace. The variants are: