As I understand it, Part No. 11 11 1 261 739 is an upgraded rear main seal design. It looks remarkably different than the original spring-actuated lip seal. I've read it has a teflon sealing surface and therefore should be installed dry. This is consistent with my experience on Cummins 12V diesel engines that use teflon main seals front and rear. I've also read that the BMW seal should first be soaked in hot oil before installation. What's been your experience? Thanks.