The Mercedes-Benz SLK will receive new EU6-compliant four-cylinder engines and an optional nine-speed automatic gearbox on selected models as part of a 2015 update. A series of running changes will be made to the two-seat roadster prior to the arrival of a facelifted model carrying the new SLC name in early 2016.
The turbocharged 2.0-litre four-cylinder petrol engine used in the entry level SLK200, the M271, is replaced by a newer unit, the M274. It delivers the same 181bhp but gains 22lb ft, taking peak torque up to 221lb ft. In combination with the standard six-speed manual gearbox, its 0-62mph sprint time is reduced by 0.4sec to 6.9sec, while combined fule consumption improves by 5.5mpg to 49.6mpg.
Further up the line-up, the SLK250 is replaced by the SLK300. It runs the same M274 designated engine as the SLK200, but in a higher state of tune. Power is up by 41bhp at 242bhp, while torque extends by 45lb ft to 273lb ft. Fitted with Mercedes-Benz’s new nine-speed automatic gearbox as standard, the new SLK300 hits 62mph from standstill in 5.8sec – 0.8sec inside the time of the outgoing SLK250. Claimed fuel consumption of 48.7mpg is a 7.8mpg improvement over that of its predecessor.
On the diesel side, the SLK250 CDI is replaced by the SLK250d. he revised model uses the same turbocharged 2.2-litre four-cylinder diesel engine as before, the OM651, producing 201bhp and 369lb ft. It now comes with urea injection technology for reduced NOx emissions.
Rather than being offered the choice of a standard six-speed manual or optional seven speed automatic gearbox, buyers of the the sole diesel model in the SLK line-up now receive a nine-speed automatic gearbox as standard. The new gearbox helps cut the 0-62mph time by 0.1sec to 6.6se, while contributing to a 5.3mpg improvement in combined fuel consumption at 64.2mpg.