Inside, customers can order aluminum pedals, stainless-steel scuff plates and Mastik leather or Alcantara upholstery.
The four-cylinder engines can be equipped with ECO PowerXtra CGI auxiliary control modules which are "custom-tailored to each respective engine variant and can be installed by any authorized Mercedes-Benz dealer in less than an hour thanks to their ‘plug and play' design." It enables the SLK 200 BlueEFFICIENCY to produce 209 PS (154 kW / 207 hp) and 280 Nm (206 lb-ft) of torque - an increase of 26 PS (19 kW / 25 hp) and 30 Nm (22 lb-ft).
On the other hand, the SLK 250 BlueEFFICIENCY produces 230 PS (169 kW / 226 hp) instead of the standard 204 PS (150 kW / 201 hp). An optional intercooler and wastegate valve can boost the output to 240 PS (176 kW / 236 hp) and 370 Nm (273 lb-ft) of torque, which enables the roadster to accelerate from 0-100 km/h in 6.2 seconds and hit a top speed of 248 km/h (154 mph).