Bob. So tell me a little about achaeffers oil. I found there web site and read thee History but what about their oil. How much would a case of 15-40 Deisel cost me what is the price per Qt? Can Schaeffers go on extended drains? Is all there oil green, can I order from you, is there or do you know a local rep in the Dallas area that I could contact, can I order directly from Scaeffers? I know this is alot of questions but what can I say I have always been intersteaded in oil ( I get that from my Da. ) I belive it is the life a an engine. All things being equal on a gas engein if good mant is kept and serv provided there is no reason a gas engine cannot go 200,000 easy, and diesels a million. Thanks. Brian.