For years my local dealership has been swearing that if you have a turbo engine you better prefill before starting. When I had my turbo Daytona,they told me point blank I'd better prefill it by cranking the engine over with the coil wire grounded. They claimed they had actually replaced some turbos and had seen premature turbo failures due to oil changes when people started them up with dry filters. When the CTD's came along, they added these engines to the list. Bottom line, I prefill the filter on my CTD and did on the Daytona until I finally wore it out. The other engines I really don't see a need and never have prefilled.