Porsche engineers may be breathing a clean-air sigh of relief as the results from the independent EQUA Index NOx tests show the new four-cylinder 718 Boxster S has achieved a best-possible A-rating for its low emissions.
It’s an excellent result for a sports car – although enthusiasts may still be questioning Porsche’s four-cylinder turbo move: the (admittedly much more expensive) Porsche 911 Carrera S Coupe was also given an A-rating for NOx emissions…
Other new cars tested that gained the top A rating this month were the Ford Focus RS and Audi TT 1.8 TFSI Sport; indeed, nine of the 10 petrol cars tested this month scored the top A rating.
In contrast, the best-ranked diesel models tested only scored a C-rating; they were the BMW 320d ED, Volkswagen CC 2.0 TDI and Skoda Superb 1.6 TDI. Other diesels performed worse still.
This, says Emissions Analytics – the organisation behind the EQUA Index testing regime – proves that petrol-powered sports cars are capable of lower NOx emissions than regular diesel-powered saloon cars.
A C-rated car meets the Euro 5 limit for diesels, rather than the current Euro 6 standard, and is similar to the generous 2.1 conformity factor for Euro 6 diesels under the forthcoming new European ‘real world’ drive cycle tests.
An A-rated car, in contrast, meets Euro 6 emissions with ease; NOx emissions are almost non-existent. Whether enthusiasts consider that enough to justify a four-cylinder turbo Porsche is another matter…