Euro 5
Applies to all new cars registered from 1 January 2011
Benefits: Heralded the introduction of diesel particulate filters (DPFs) for all diesel cars. A particulates limit was also introduced for direct-injection petrol engines.
An additional limit on the number of particles emitted by diesel engines was also introduced for cars registered from 1 January 2013.
Euro 5 emissions limits (petrol) CO: 1.00g/km HC: 0.10g/km NOx: 0.06g/km PM: 0.005g/km
Euro 5 emissions limits (diesel) CO: 0.50g/km HC + NOx: 0.23g/km NOx: 0.18g/km PM: 0.005g/km PM: 6.0×10 ^11/km
Read more – Should I buy a petrol or diesel car?
Euro 6
Applies to all new cars registered from 1 September 2015
Benefits: A 67% reduction in the permissible levels of nitrogen oxides in diesels and the introduction of a particle number limit for petrols.
Car makers are using two methods to meet these strict diesel limits. The first is selective catalytic reduction, which involves a liquid that converts nitrogen oxide into water and nitrogen being squirted into the car’s exhaust.
Alternatively, an exhaust gas recirculation system is fitted, which replaces some of the exhaust gas with intake air to reduce the amount of nitrogen that can be turned into NOx.
Euro 6 emissions limits (petrol) CO: 1.00g/km HC: 0.10g/km NOx: 0.06g/km PM: 0.005g/km PM: 6.0×10 ^11/km
Euro 6 emissions limits (diesel) CO: 0.50g/km HC + NOx: 0.17g/km NOx: 0.08g/km PM: 0.005g/km PM: 6.0×10 ^11/km
How effective have the Euro standards been?
According to figures from the Society of Motor Manufacturers & Traders (SMMT), the Euro emissions have had a significant influence in reducing emissions.
It states that since 1993, carbon monoxide levels have been cut by 82% for diesel-engined cars and 63% for petrols and particulate matter is down by 96%. Since 2001, nitrogen oxide is down by 84% and hydrocarbons are down by 50% in petrol-engined cars.
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