Euro 5 further reduces the permitted amounts of carbon monoxide, hydrocarbons, oxides of nitrogen and particulate matter in car and light commercial exhaust gasses. The stricter standards came into force across the European Union for newly-launched models in September 2009, and will apply to all cars on sale (regardless of their original introduction dates) from January 2011.
The problem for the RX-8 was its rotary engine. Although powerful, generating 228 bhp in its final guise, it was awfully inefficient. For example, combined cycle fuel consumption was a fairly pathetic 24.6 mpg, while CO2 emissions were 299 g/km. By comparison, a BMW 330i Coupe with 272 bhp manages 38.9 mpg and 173 g/km.
Mazda could have modified the RX-8 to be Euro 5 compliant, but the company soon realised the cost and effort involved didn’t make that option worthwhile.
But this doesn’t mean the end of rotary engines altogether. Mazda is going to persevere with the technology, and is currently working on a replacement for the RX-8. It’ll need to ensure that model’s emissions comply not only with Euro 5, but also with the even tighter Euro 6 rules that come into force from September 2014. Hopefully the fuel consumption will improve a bit, too.