For the 1994 model year, Mercedes-Benz revised the naming system. Models were divided into "classes" denoted by an arrangement of up to three letters (see "Current model range" above), followed by a three-digit (or two-digit for AMG models, with the number approximately equal to the displacement in litres multiplied by 10) number related to the engine displacement as before. Variants of the same model such as an estate version or a vehicle with a diesel engine are no longer given a separate letter. The SLR, SLS and GT supercars do not carry a numerical designation.