Jaguar has announced a range of new and modified engines across its saloon ranges.

The main idea is to drastically cut CO2 emissions and therefore tax for company car drivers. The brand-new engine is the 3.0 V6 supercharged petrol which will also go into the F-Type sports car next year. The 335 bhp unit emits 224 g/km of CO2 (30 mpg) in both the XF and XJ, which means it avoids the punitive Band M road tax of the now-obsolete 5.0 V8 normally aspirated petrol engine.

The other big change is a revised version of the 161 bhp 2.2 diesel, which sees its CO2 output drop from 149 g/km of CO2 in the XF saloon to 135 g/km of CO2 (55.4 mpg). That is still not quite equal to the 129g/km of the best Audi A6 and Mercedes E Class models, but it is getting closer. There is also a new option of a 197 bhp 2.2 litre, which has an identical CO2 output and fuel consumption to the lower powered version.

Finally, the 3.0 V6 diesel has seen its emissions cut as well. The saloon is now 159 g/km (46 mpg), which means it gets under the crucial 160g/km limit for company cars. Unfortunately the V6 diesel estate just fails to make it, with a figure of 163 g/km of CO2 (47 mpg).

The new V6 supercharged engine is also likely to feature in the next-generation Range Rover, which could have lower CO2 emissions than the current Range Rover diesel.