Mercedes-Benz SLK-CLASS Operator's Manual page 208

Technical data
Electrical system
Model
Generator (alternator)
Starter motor
Battery
Spark plugs
Electrode gap
Tightening torque
446
SLK 280
14 V/150 A
12 V/1.4 kW
12 V/62 Ah
NGK PLKR 6A
0.031 in (0.8 mm)
15 – 22 lb-ft (20 – 30 Nm)
SLK 350
14 V/150 A
12 V/1.7 kW
12 V/74 Ah
Bosch Platin Y 7 MPP33
NGK PLKR 6A
0.031 in (0.8 mm)
15 – 22 lb-ft (20 – 30 Nm)
SLK 55 AMG
14 V/150 A
12 V/1.7 kW
12 V/74 Ah
NGK IFR6D10
0.039 in (1.0 mm)
18 – 22 lb-ft (25 – 30 Nm)