When you buy a name brand motor oil, Chevron, Pennzoil, ect, you are buying the additive package. In college, we ran experiments with various oils that all had the same SAE/API minimum specifications. The house brand/generic low cost oils would loose there lubricating properties sooner than the major brand oils. Do not go cheap on your motor oil. Use a name brand petroleum based oil and change the oil and filter frequently. The Technical reference guide states that you should use API Service SF, above 10F, 20w/40 or 20w/50 and below 10F, use 10w/50. Scott Mueller 002981 RNDOLA -----Original Message----- From: Scott McMullan [mailto:mcmullan@xxxx] Sent: Saturday, January 03, 2004 9:52 AM To: dmcnews@xxxxxxxxxxxxxxx Subject: [DML] 15W40 oil brand I was looking through a local Pep Boys store the other day, and had a difficult time locating 15W40 oil. As it turns out, they only seem to carry one brand of that weight, and only in gallons. I've never heard of this oil brand (began with an R, forget the full name). The package had a yellow shell on it, so I wonder if maybe the oil is actually produced by Shell Oil, and distributed under a strange name? While I know there are many conflicting ideas about what kind of oil to use in the PRV, I was wondering if anyone had a strong opinion one way or another about using an oddball oil brand, as opposed to the better known ones. I had no trouble finding the GTLMA fluid for my clutch, which was nice to see.