You know, I worked in retail automotive when that stuff was around, and similar products. The only proof they ever offered were independant studies which as i’m sure you know are easily pointed in whatever direction they want. The only peopls I trust are the Society of Automotive Engineers. They are tasked with both providing ratings and testing lubricants to make sure they adhere to governement standards the most noteworthy one being a MS or military specification. They do not mess about at all in their specifications. If you’ve ever read a military manual you will know what I’m speaking of. Those products do actually provide excellent lubrication. They are much more slippery than motor oil and able to withstand more pressure as well. I knew a mechanic that modified race engines, not on the Kieth Black level but he used many of his tricks and he used it for assembly. On the whole, in my opinion, too much is made of lubricants. For guys like you and me just picking a good brand and sticking with it is more than sufficent. If you would like my personal opinion I use Castroil. I have taken apart many engines after using it from big block fords to chevy aluminum engines and have found it to remain stable and clean after much abuse. Perhaps **Rick ** and Gary T would also be so kind as to mention their favorites. Both guys have far more experience than I and I don’t remember either of them telling us before.
I’m not too sure about the usefulness of this testing protocol. Here’s a quote from the article:
“Our test conditions were grueling, to say the least. The typical Big Apple cab is driven day and night, in traffic that is legendary for its perversity, by cabbies who are just as legendary for their driving abandon.”
It’s always been my understanding that the taxis which were tested were operated continuously, as in 24 hours a day, 7 days a week. This would mean that the engines in these cabs were essentially never run while cold. Yet most your car’s engine wear occurs before the engine reaches operating temperature.
Therefore, if a particular motor oil were actually far superior in providing protection to a cold engine - such as is the case with synthetics - that superiority shouldn’t be expected to be demonstrated by these tests.
There are few subjects that will create more contention on an automotive board than which oil is best. The amount of rumor, innuendo, and outright lies are amazing. For example I had one guy tell me flat out that if I used anything except WD-40 on the cylinder walls when assembling an engine the rings would never seat. :rolleyes: :dubious:
I asked him two questions:
- WD-40 didn’t come to the public until the 1950s, are you telling me that no engine built before that ever had the rings seat in?
- Can you provide a cite that carmakers buy WD-40 by the tanker load for their engine plants?
(reason #42 why I like the SDMB people don’t freak and call you an asshole when you ask for a cite)
The following is my opinion backed up by some info I have learned over the years. Castrol is a very good oil. One independent imported car shop I worked for back in the early 1970s had their comeback rate on VW engines cut in half by switching to Castrol. I have also been told by factory engineers working for Volvo that they like Castrol because Castrol uses a pretty middle of the road base stock, but they use a superb additive package. I would note that Volvo recommends Castrol, but the engineers that I was speaking to were way more concerned with what works rather than what type of marketing agreement is in effect.
Back in the day, I had a car that had bad timing gears. The gears would knock almost like a rod knock at idle. I found that when I changed my oil with Valoline the noise would go away for maybe 1,000 miles. If I changed my oil with Castrol or Kendall GT-1 the noise would go away for about 2,000 miles.
As far as dislikes go, I am not a fan of Valvoline, Pennzoil or Quaker State. IMHO the base stock for QS and PZ is inferior. I have seen some bad things with Valvoline also.
Philster while I agree with you for the most part, I would note that many cars living in colder climates (read NE US) have problems with sludging. This can occur with factory recommended oil changes, using factory recommended oils. Synthetic oils can lessen this problem. This problem exists across the different car makes and different brands of oils. If you observe sludging starting to occur, I would strongly suggest you consider switching to a synthetic.
I can confirm absolutely that as of 2004, at least one engine plant does not buy tankers full of WD-40 for its engine processes or hot-testing area.
Lots of WD-40 available in the stores for trades’ use, though. 
Hey Rick-
Go check this board out- it’s got some really interesting and potentially eye-opening stuff, especially re: Pennzoil & Quaker State.