Yeah, the 193 is the chassis code for the Crossfire but this uses the Mercedes parts numbering system. For all intents and purposes, the XF is a 170.465 (2004 SLK 320). As you'll find on XFs (and was mentioned above), 193 is exclusively a Crossfire part. For example, the headlight assemblies, which are made in Belgium. As with most Mercedes products, there's a lot of parts sharing. For example, the lower control arms on an XF should be a 202 part number, indicating that the part was originally used on the 202 chassis MB (a C-Class up to 2002). Not all SLK parts are 170, just those specifically used first on that model....which has a lot of 202 parts on it. As for the engine / Tranny: Yes, the engine is a 112 code....the next to the biggest displacement. In the US, the M112 ranged from a 2.6 liter(C240) to a 3.7 liter(ML350). The auto transmission is super tough (but service it every 40k) and is known as a 722.6. It's a staple in most Mercedes products from about 1996-2005. For clarification for the original poster, the M111 is a 4 cylinder engine mostly used in the C-Class (W202) in both N/A and Supercharged forms.