The new Honda Civic will come with a reworked version of the manufacturer's 2.2-litre diesel engine which emits just 110g/km CO2.
The new version of the popular family hatchback will reduce emissions over the old Civic by as much as 29g/km while still offering a boost in power by 10bhp.
The reduction in CO2 has been achieved through a number of enhancements to the existing engine, including a revision to the oil flow, a revision of several components to reduce friction and the addition of a stop start system, which drops emissions by 5g/km alone.
Honda says it has also worked hard on the new car's aerodynamics to improve air flow and reduce drag, as well as improving its high-speed stability.
Despite the changes, Honda has managed to retain the 148bhp power output of the engine that is in the Accord, meaning the Civic should also hope for a similar acceleration time around the 10 second mark.
"To achieve a good CO2 figure, you need to optimise every aspect of the car," says Katsushi Watanabe, Honda's development leader for the engine. "Reducing the emissions was our key target and we're proud to say that we have achieved this without compromising the high performance character of the engine. We want our customers to have fun when they drive this car."