[DonSor]

While we're on the subject some vehicles do not require to change oil until 7500 miles which is possible because of the quality of oil. However, since filters don't get changed until the oil change, what happens to the pressure drop in the oil filter after long mileage, meaning that as the filter does its job filtering, doesn't that affect the amount of oil going through through the filter. some commercial engines have oil bypass whereby after the pressure in the filter reaches a certain point, it will bypass the oil to ensure sufficient lubrication. My point is that oil filters do not cost much so will it be prudent to replace the oil filter at lets say 4K miles (half the mileage) than that of the syn oil at 8K miles? This is true of the air filters and that's why I use the K & N air filter whereby I service it everytime i change oil.