For BMW 6' E64 LCI (04/2006 — 07/2010). For BMW 6' E63 LCI (04/2006 — 07/2010). For BMW 6' E64 (09/2002 — 07/2010). For BMW 6' E63 (05/2002 — 07/2010). The primary role of a fuel tank cap is to create a tight seal that prevents fuel vapor from escaping the fuel tank through the filler neck.
