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Read our primer articles on High Mileage Oil, Synthetic Oil and Kinematic Viscosity

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hi moontan, for the past three and a half years I have worked as a mechanic at my family owned business (which my father has ran for 25 years) and I have seen a lot of cars with internal engine problems, but to make this story short one incident that I remember was with a 1986 Chevy S-10 4x4 with a 2.8 V-6. It came in with a blown motor and the owner didn't know why. After we got the engine out we were going to drain the oil in it as we do in all engines we take out and when I took the drain plug out nothing came out. After it sat there for about 15 or so minutes big glops of grease or so we thought started to come out. At first we thought that this person just never changed his oil. Later when the person came to get his truck we told him of our incident and asked him how often he changed his oil and he told us that he changed it every 3,000 or less miles and he even proceded to show us the bills that he kept in his truck that he had for his records. But what caught our eyes was that the place he took it featured Pennzoil and Quaker State which are the same company.So to conclude our theory we figured since when he got his oil changed the truck engine was hot the oil was thinner and when the oil cooled down it became thick like grease. So from that day on he has never used either brand in in all truth I don't recommend it either. If you were to ask me what to use I would say either Castrol or Mobil (I own a 1999 Subaru Impreza and I use Castrol Syntec 5w-30 in it) Just stay away from Pennzoil and Quaker State!
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Pennzoil has invested hundreds of millions of dollars to develop quality hydro-isomerized (hydrowaxed, hydrocracked) refining technologies. And when Consumers Reports tested oils about 10 years ago, Pennzoil was one of the few companies where the oil vis on the label was consistently the oil vis in the bottle, and their products trended to stay in grade (shear resistant) well. So I say they are a first rate "biggie", with all the good and bad. QC in the bigs is only fair across the board in my opinion. That is why I tend to use products that I have analyzed myself in our Lab, and which have showed high quality, innovative additive technology, pure base stocks, etc. This includes Lubrication Engineers 8130 engine oil, and 607 gear oil (90w), Amsoil Series 2000, Pennzoil Multi-Vis (and some of the old Turbo oil before it was discontinued), Red Line, Motul, and a few more.
A. Everybody has one engine that died of a horrible lube failure story, so the S-10 story doesn't mean much. Especially an engine that had seen a steady diet of quicky-lube service, an owner that didn't even check the oil with a blown engine, and a design prone to coolant leaks into the oil (pretty much all GM 60 degree v-6's). I've personally seen a Mazda where one of the quicky lube places left the rather hard to reach filter (a Fram) on for many oil changes, probably close to 20k. I've heard reputable accounts of "Caker-State", Mobil, Castrol, and Texaco causing engine failure...and frankly I'm not going to condemn any brand based on a few failures and a bunch of parts store hanger-flying.

B. Road Rage is right, Pennzoil has a soild product, in my oppinion their 15W40 is neck and neck with Delvac and Delo. The rest of their products are turning in good wear #'s too.

C. Oils do change over time! Fortunately, we have oil analysis, MSDS sheets, and standardized tests to detect when a formula changes. Examples here would be Castrol's (American) switch to Group III, and on the other side, the strong additive package in Motorcraft 5W20, or the switch to Group II/III basestocks in conventional oil (Chevron, Pennzoil, etc).

You will probably be just fine with the Pennz petroleum oil, however, with vehicles that nice why not use the best, especially when it is cheaper? With Amsoil you don't have to worry about the sludge problem, and when using extended drain intervals you will actually be paying LESS for the oil that what you pay now for the Pennzoil.
Hi guys,

As a brand Pennzoil has an excellent reputation and is possibly the largest selling engine oil brand in US. All this could not have been possible without consistently meeting quality standards. Incidently Penznoil is now owned by another Petrochemical giant, Shell, which is also quality conscious.

With my 18 years with Castrol ( in Sales ) I can say and even the top companies do slip. The important thing is how the company reacts to complaints and product failures and if corrective measures are actually taken.

On the other hand,(in India) there is a large problem due to "spurious oils" put into containers of top brands like Castrol. So Castrol now uses new pilfer proof techniques while packaging its products.

Hussam Adeni
A nice example of a company responding to complaints would be Shell refunding money for those who complained about Rotella 5W40 from the bad smelling batch last spring.

As far as companies slipping in performance, there is no subsitute for spec sheets, MSDS sheets and oil analysis to keep them honest.

Pilfer proof oil bottles is an interesting thought. Here in North America, a bigger problem is shady quick lube places not actually perfroming services and selling wallet flushes.

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