Many of Volkswagen's latest Euro 6 diesel and petrol-engined cars have been given top ratings in new emissions tests that measure the levels of Nitrogen Oxides (NOx) being emitted during real-world driving conditions.
The EQUA Air Quality Index, launched by vehicle emissions measurement company Emissions Analytics, has tested some of the latest models from a range of car manufacturers. Cars tested are given a rating from 'A' to 'H' depending on how clean they are, with the findings openly published and freely available. The ratings contrast with official tests, which are conducted in laboratory conditions to ensure repeatability and which result in either a 'pass' or 'fail' result for manufacturers.
The first batch of data focusing on 440 cars - including 112 vehicles equipped with the latest diesel and petrol Euro 6 engines - shows that many models from within the Volkswagen Group have been given an 'A' rating, indicating they meet the required Euro 6 lab test limits.
Top-ranked petrol models include the Audi A1 (123bhp 1.4-litre), A3 (148bhp 1.4-litre), A4 (187bhp 2.0-litre), A5 (170bhp 1.8-litre) and RS3 (362bhp 2.5-litre), Seat Ibiza (108bhp 1.2-litre and 148bhp 1.4-litre) and Leon (148bhp and 150bhp 1.4-litre and 261bhp and 286bhp 2.0-litre), and Volkswagen Caddy (123bhp 1.4-litre) Golf (115bhp 1.0-litre, 138bhp 1.4-litre, 218bhp and 296bhp 2.0-litre) and Polo (89bhp 1.2-litre).
'A'-graded Euro 6 diesel models include the Audi A5 (161bhp 2.0-litre), Skoda Superb (148bhp 2.0-litre) and VW Golf SV (148bhp 2.0-litre), VW Passat (118bhp 1.6-litre), VW Scirocco (148bhp 2.0-litre) and VW Touran (108bhp 1.6-litre).
Other manufacturers with 'A' rated Euro 6 compliant petrols include: BMW, Citroën, Hyundai, Infiniti, Kia, Mercedes, Mini, Smart, Suzuki, Vauxhall and Volvo. BMW was the only non-VW Group manufacturer to score an 'A' rating with a diesel engine, with the 184bhp 2.0-litre unit powering the 3 Series.
However, the lowest rated Volkswagen car powered by a Euro 6 diesel - the 89bhp VW Polo powered by a 89bhp 1.4-litre engine - was rated only as an 'F', indicating it wouldn't meet any former Euro standards, and emits six to eight times the amount of NOx allowable in today's Euro 6 tests.
Furthermore, three vehicles powered by Euro 6 diesel engines have so far been given an 'H' rating - indicating that they are emitting high levels of NOx up to 12 times the legal standard for Euro 6 compliancy. Those are the Fiat 500X (118bhp 1.6-litre diesel), SsangYong Korando (176bhp 2.2-litre diesel) and Audi A8 (247bhp 3.0-litre diesel). The lowest-rated petrol-powered car on the list was the Ford Focus (123bhp 1.0-litre), which received an 'E' rating, meaning it only meets Euro 3 standards.