Both the new models can run on a 30% mix of bio-diesel and are twinned with a six-speed manual gearbox.
The range-topping 136hp 2.0HDi 16V unit returns 40.0 mpg on the combined cycle, produces carbon dioxide emissions of 188g/km and is fitted with a diesel particulate filter system. The engine has a top speed of 118mph and replaces the 130hp 2.2HDi unit.
The 120hp 2.0HDi 16V engine returns 41.0 mpg and produced carbon dioxide emissions of 182 g/km. It has a top speed of 112mph. The current 110hp 2.0HDi 16V version will continue as an automatic only.
Prices for the new diesel models start at £18,000 for the 120hp 2.0HDi 16V LX and £20,025 for the 136hp 2.0HDi 16V SX, including £3,000 cashback throughout August.