'94 LS400 6-7k/6mo with dino, 12-15k/12mo with syn, oil filter once a year, i.e, re-use oil filter with dino but not with syn.
'00 E430 10-13k/12mo with syn only, cartridge paper oil filter every oil change. The newer fleece filter has "an advanced filter media that allows the increase of service intervals with better filter efficiency", if I buy this fleece filter I may re-use it.
'04 S2000 6mo with dino, 12mo with syn, oil filter once a year. Annual mileage for this car is about 5-6k. I may increase oil filter usage to 2 years, i.e., filter is changed only at 4th oil change with dino or 2rd oil change with syn.
50+