I have a new twist on the age-old "which oil is better" phenomena. I recently started an onsite oil changing service, and am looking at several distributors to use as my "featured oil." I am opposed to using a product I wouldn't trust in my own car. I have been heavily considering going through the MobilExxon distributor, as their oil is relatively low cost and performance seems to be favorable. This company also sells Purolator filters with the Mobil name imprinted on them, which filter seems to be good among its low-cost competitors (i.e. Champion). The Chevron distributor does not sell filters, which means that I would get a better price from Mobil for buying more products in greater bulk, blah, blah, blah. What is your opinion?