Volvo's engine range is launching two new four-cylinder 1.6-litre petrol engines, T3 and T4, featuring the very latest direct injection technology. The GTDi (Gasoline Turbocharged Direct Injection) concept was developed to offer improved fuel consumption without compromising on performance. The 1.6 GTDi T3 features 150 PS while the T4 offers 180 PS and both will be available in the all-new Volvo S60 and V60 in late 2010.
The 180 PS T4 engine delivers maximum torque of 240 Nm from just 1600 rpm all the way up to 5000 rpm. An automatic on-demand overboost function provides a massive 270 Nm of torque which results in excellent pulling power across the entire rev range. The torque curve is relatively gentle, providing a comfortable driving experience. The 150 PS T3 version offers 240 Nm of torque.
"Small, high-performance GTDi engines are a part of our bid to get more energy out of smaller engines" says Magnus Jonsson, Senior Vice President Product Development at Volvo Cars.
On both 1.6-litre engines, each injector has been positioned centrally above the piston, just beside the spark plug. The injectors have six holes each which offer finely atomised fuel distribution.
The centrally located multi-hole injector makes it possible to control fuel dosage precisely. In cold starts, the fuel is sprayed into the middle of the combustion chamber just prior to ignition. The high fuel injection pressure of 100 bar means that preparation is perfect and less fuel ends up on the cold combustion chamber walls. This helps cut emissions and considerably reduces the amount of fuel consumed. Another effect is a major reduction in the amount of soot particulates compared with a side-positioned injector.
In cold starts, this injection technology also contributes to quick heating of the catalytic converter, which in turn speeds up the exhaust cleaning process.
Direct injection gives a high fill rate in the combustion chamber. Apart from effective combustion and lower emissions, this also helps the turbo start up earlier and provides swift response even from low engine revs. This promotes fast acceleration and good driveability from low speeds.
"This is the most modern injection technology in existence and Volvo played a major role in its development," says Magnus Jonsson. "Our cooperation with Bosch, which manufactures the system, has been ongoing for a number of years and is highly successful."Published 31 August 2010