I've used mobile 1 for 5 years with no problems. In my Z I change oil 3-4miles. My daily driver explorer I will change at 5000. With my Z the oil is always clear looking. The explorer is a little darkened. I started mobile 1 in the explorer at 62K 20 months ago. I have 135k on it now.I will be looking into the new mobile clean drive 5000 and 7500 mile oil. Frank