I'm thinking about buying a five series bmw, around the 1995 year range, this will also be my first Bimmer. I'm getting conflicting information on the five series regarding the engine, that it's made of a material called nikosil, and it needs to be rebuilt prematurely. Is this true in all five series or around this time frame? My other question is, is there a big difference between the 4.0/3.0 power wise. If anybody could help I would appreciate it.