With plans for similar emissions-based taxation schemes like London’s congestion charge as well as tough new low CO2 emissions regulations planned for Europe from 2012 onwards, carmakers are focused on cleaning up tailpipe emissions as well as offering more models with lower CO2 levels than currently provided. One of the most active is BMW, which has already shown a 119g/km of CO2 1-series and is now reportedly set to release a sub-120g/km 3-series saloon.

According to latest reports, BMW is prepping a version of the 318d that will have a sub-120g/km CO2 level. The current 318d produces 123g/km but with some minor revisions, such as improving the aerodynamics and gearing as well as adding lower rolling resistance tires, BMW will be able to reduce the emissions, reports AutoExpress.

Such a vehicle would receive a 100% refund on London’s congestion charge as well as lower registration tax also in the UK as it would qualify for the Band B taxation category. A BMW spokesman also revealed that any revisions made to the 3-series would flow-on to the 1-series, making the compact hatch even cleaner, and could potentially feature on other models within the line-up.