European emission standardPortugal

An introduction to the traffic rules and road signs of Portugal. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.

For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.


29. European emission standard

A European emission standard, commonly called a Euro standard, is a European vehicle classification based on limits for pollutants emitted by vehicles and their engines. Successive standards, such as Euro 4, Euro 5 and Euro 6, introduced progressively stricter requirements for pollutants such as nitrogen oxides, particulate matter, carbon monoxide and hydrocarbons.

A vehicle's Euro standard is determined as part of its type approval and depends on factors including the vehicle category, fuel type and applicable emissions legislation when it was approved. Euro standards may also be used by authorities to determine access to low-emission zones, but local access rules vary between countries and cities.

European emission standard
Chart comparing European exhaust-emission standards for diesel cars.
Wikimedia.org • Rfeba • CC0
What is a European emission standard?

A European emission standard, or Euro standard, classifies vehicles according to the emissions requirements they had to satisfy when approved for use in the European market.

🔗 legislation.gov.uk • Regulation (EC) 715/2007, Annex I, Euro 5/6 tables (UK official legislation copy)

🔗 consilium.europa.eu • Council of the EU, Euro 7 adoption explanation, 12 April 2024

What do Euro 4, Euro 5 and Euro 6 mean?

Euro 4, Euro 5 and Euro 6 identify successive stages of European vehicle-pollutant requirements. The applicable limits depend on the vehicle, engine and pollutant, so a higher number does not mean that every individual numerical limit changed. Later stages can also alter testing and durability requirements.

🔗 legislation.gov.uk • Regulation (EC) 715/2007, Annex I, Euro 5/6 tables (UK official legislation copy)

🔗 consilium.europa.eu • Council of the EU, Euro 7 adoption explanation, 12 April 2024

Can petrol and diesel vehicles with the same Euro number have different emission limits?

Yes. The applicable emission limits and testing requirements can differ according to the vehicle category, engine and fuel type even when vehicles belong to the same general Euro generation.

🔗 legislation.gov.uk • Regulation (EC) 715/2007, Annex I, Euro 5/6 tables (UK official legislation copy)

🔗 consilium.europa.eu • Council of the EU, Euro 7 adoption explanation, 12 April 2024

1 Portugal 2 Motorway 3 Zone 4 Speed limit 5 Bike path 6 Bus stop 7 Dead end 8 Stop sign 9 Roundabout 10 Railway crossing 11 Mandatory direction 12 School area 13 Overtaking 14 Crossing animals 15 Wrong-way driving 16 Traffic lights 17 Traffic mirror 18 International border 19 Parking 20 No parking 21 Disabled parking 22 Reversing 23 Tourist attraction 24 Licence plate 25 Charging station 26 Bus 27 Police 28 Ambulance 29 European emission standard 30 Pothole 31 Path 32 Particulates 33 Air pollution 34 Rush hour 35 Road code 36 Street gutter 37 Cargo bike 38 Forestry vehicle 39 Construction vehicle 40 Semi-trailer truck 41 Trolleybus 42 Speed pedelec 43 Delivery vehicle 44 Idling 45 Tow truck 46 Four-wheel drive 47 Bicycle 48 Motorcycle equipment 49 Rail track 50 Caravan 51 Trailer 52 Tow hitch 53 Fire truck 54 Siren 55 Convoy 56 Emergency vehicle lighting 57 Agricultural machinery 58 Electric bicycle 59 Electric vehicle 60 Pedelec 61 Quadricycle 62 Microcar 63 All-terrain vehicle 64 Van 65 Recreational vehicle 66 Scooter 67 Trikke 68 Personal mobility device 69 Skateboard 70 Segway 71 Kick scooter 72 Roller skates 73 Mailman 74 Hitchhiker 75 Toddler 76 Child 77 Disability 78 Motorail 79 km/h 80 mph 81 Speedometer 82 Ride height 83 Dirt road 84 Driving 85 Start-stop system 86 Manual transmission 87 Automatic transmission 88 Throttle 89 Tachometer 90 Steering wheel 91 Power steering 92 Visual scanning 93 Mirror 94 Fuel 95 Fuel gauge 96 Petrol 97 Diesel 98 Diesel exhaust fluid 99 Car insurance 100 First aid kit ...