Jaguar’s 2014 XF features a new four-cylinder, 2.2-liter diesel ECO2 engine; the MY14 XF with the 161 hp (120 kW) ECO2 engine is capable of achieving 48 mpg US (4.9 l/100km) with a CO2 figure of 129 g/km. The 400 N·m (295 lb-ft) engine is paired with an eight-speed automatic transmission.
The MY14 XF with ECO2 engine is offered with an Intelligent Stop-Start system that uses a Twin Solenoid Starter (TSS) to shut down the engine when the car comes to a halt, helping to reduce emissions and improve fuel consumption.
The system also offers “change-of-mind” functionality, enabling the engine to quickly restart even during its rundown phase to allow the driver to, for example, exploit a gap in traffic at a junction.
An illuminated “ECO” symbol appears on the Instrument Panel when the engine has been stopped by the system. Stop-Start can be turned off manually, but it will automatically be turned on again for the vehicle's next journey with every ignition cycle. The system operates in all modes apart from Reverse.
The MY14 XF has a secondary battery fitted specifically for engine re-starting, meaning that all the normal car systems—such as the entertainment system, the ventilation and lights—continue to receive power from the standard car battery and are unaffected by the re-start. In addition, a control system ensures that the Stop-Start operation only occurs when the car does not require the engine for other functions.
Jaguar’s new 2.2L ECO2 diesel also has new larger Exhaust Gas Recirculation valves and a revised cooling assembly which combine to reduce emissions figures by a further 6 g/km of CO2 over the 2013 Jaguar XF.