A few 'ponderings' on this subject......anti-drain back only helps if the filter mount position is above the main oil gallery & the base of the filter face upward or horiz....ALL engings on cold start up have bearings and crank in a 'metal to metal condition as the oil seeps out over night they contact,only way round this is an Accusump or a'snake oil' plating additive!!!!.....oil temp is the killer along with 'slow flo' 20W50 for example....50% of modern engine cooling is via the oil, in a DOHC motor far more 'exposed' internal casting area transfers heat to the oil vs say a pushrod engine.The Duratec raises it oil temp VERY quick....high operating oil temps,whatever grade,are death to an engine under load conditions.......my 2 1/2 cents!!!
