I recently have changed my oil filter brand from Fram to Wix. I had run across a revealing web site that showed comparisons between different brands of oil filters. I couldn't believe other brands had twice the area of filtration media. I run Amsoil and have the oil changed at extended periods of operation. I hope I haven't caused myself any problems. I only used a quart of oil in 12,000 miles. The engine only has 39k miles and most of them were city driven.