The new standards, to be introduced on 22 April, will bring London taxis into line with those which other diesel vehicles must already meet.
The new limits will be: for non-turbocharged engines2.5 m-1 and for turbocharged engines3.0 m-1.
The arrangements for testing a taxis exhaust emissions at MoT garages before the vehicle is presented to the Public Carriage Office for its annual inspection will remain unchanged.
'The introduction of these tougher standards for London taxis is in line with the government's policy that all diesel-engined cars should be tested annually to ensure that exhaust emissions are kept to a minimum.'
-- There are more than 18,000 licensed taxis in London. They are exempt from the MoT testing regime because the annual test at the Public Carriage Office is considered to be equal to the MoT test.
-- Regular instrumented exhaust emission tests for London taxis were introduced on 18 April 1995.
-- The current exhaust emission limits for London taxis are: for non-turbocharged engines3.2 m-1 and for turbocharged engines3.7 m-1.
-- The new requirements will be in line with the reduced in-use emission limits for other diesel vehicles which were introduced on 25 September 1995 in order to comply with the EC Directive on roadworthiness testing.