Stuttgart  - Porsche is said to be downplaying plans to build a special economical four-cylinder version of the Boxter, the British Autocar magazine has reported, quoting company sources.

A Porsche spokesman described the report as "pure speculation." The next generation of the Boxter Roadster and the Cayman coupe would still be offered with a six-cylinder engine, the spokesman added. He pointed out that they would be more economical because of direct injection systems.

Carmakers are under pressure to comply with stricter European Union emission regulations limiting tailpipe emissions to 130 grammes of carbon dioxide per kilometre (g/km) from 2012 to 2015. The current average is just under 160 g/km. Most Porsche sports cars are well above this range.

The current Porsche Boxter emits 222 g/km. According to Autocar, a new four cylinder would be substantially lower because of lightweight materials and a turbocharged motor with an output of 147 kilowatts/200 horsepower.

Porsche's last four-cylinder engine was the entry level 968, produced between 1992 and 1995. It was the final model that evolved from the Porsche 924 and 944. (dpa)