Archive Website of the UK government

Exhaust emissions standards

The exhaust emissions standards are continually being improved, with Euro 4 being the most common standard at present. The stricter Euro 5 test is now compulsory for all new cars currently on sale in the UK. As with the fuel consumption tests a single vehicle representative of a particular version is tested.

Exhaust emission limit tables

Before cars can be sold in the European Union they must meet certain type approved standards for exhaust emissions. The figures listed in the tables should be treated with some caution. This is because the testing is carried out under controlled conditions, and the legislation allows for tolerances to be built into the published data. The tables should not be used to rank a number of vehicles for which similar figures are quoted.

Euro 4 limits - cars not exceeding 2.5 tonnes laden

The Euro 4 limits were specified for any new model types approved on or after 1 January 2005. These limits will become applicable to all models from 1 January 2007.

* CO = Carbon Monoxide
** HC = Hydrocarbons
*** NOx = Oxides of Nitrogen
**** HC + NOx = Hydrocarbons + Oxides of Nitrogen
***** PM = Particulate mass

Euro 4 limits - cars more than 2.5 tonnes laden (unladen weight between 1305 and 1760 kilograms)

The Euro 4 limits were specified for any new model types approved on or after 1 January 2005. These limits will become applicable to all models from 1 January 2007.

* CO = Carbon Monoxide
** HC = Hydrocarbons
*** NOx = Oxides of Nitrogen
**** HC + NOx = Hydrocarbons + Oxides of Nitrogen
*****PM = Particulate mass

Euro 4 limits - cars more than 2.5 tonnes fully laden (unladen weight over 1760kg)

The Euro 4 limits were specified for any new model types approved on or after 1 January 2005. These limits will become applicable to all models from 1 January 2007.

* CO = Carbon Monoxide
** HC = Hydrocarbons
*** NOx = Oxides of Nitrogen
**** HC + NOx = Hydrocarbons + Oxides of Nitrogen
*****PM = Particulate mass

Euro 5 limits - cars not exceeding 2.5 tonnes laden

From 1 January 2011, all new model types must be approved to the Euro 5 standard.

* CO = Carbon Monoxide
** THC = Total Hydrocarbons
*** NMHC = Non-methane hydrocarbons
**** NOx = Oxides of Nitrogen
***** THC + NOx = Total Hydrocarbons + Oxides of Nitrogen
****** PM = Particulate mass
******* P = Particles