This year’s Geneva show marked the 70th anniversary of Mercedes-Benz’s first ever diesel engine – a 2.5-litre four-cylinder producing 45bhp in the 1935 260D – and it celebrated the occasion by revealing five new diesel models and two diesel concepts. Headlining the diesel offensive was a triple-turbo concept version of Mercedes-Benz’s recently introduced 3.0-litre V6 common-rail engine, making its premiere in the AMG-kitted SLK320 CDI Vision. The four-valve-per-cylinder engine kicks out 286bhp and 464lb ft of torque. That’s 42bhp and 67lb ft up on Mercedes-Benz’s standard single-turbo 3.0-litre V6 oil-burner, and trumps BMW’s new twin-turbo 3.0-litre in-line six by14bhp and 51lb ft. It’s enough, according to Mercedes-Benz, to provide the compact roadster with 0-62mph acceleration in 5.3sec, just 0.4sec slower than the V8 petrol powered SLK55 AMG. Top speed is put at 155mph, with fuel consumption said to average 37.7mpg. Mercedes-Benz’s engine development boss, Leopold Mukulic, described the new engine as ‘a breakthrough in diesel performance’. However, he stopped short of confirming the triple turbo was ready to be placed into production. ‘We’re confident about its ability in a production environment, but the cost of assembly is extremely high,’ he said. Also basking in the limelight was the SL400 CDI Vision fitted with a new twin-turbocharged 4.0-litre V8 common-rail diesel. Ready for production, this powerful new engine will appear in new models including the E-, M-, R-, S- and G-class. With 315bhp and 538lb ft it develops 65bhp and 125lb ft more than the existing 4.0-litre V8 diesel.