Which Oil to Use?

We get questions — loads of questions — every single day here at Blackstone Laboratories, and easily the most common question we hear is, “What type of oil should I use?”

Because we’re an independent laboratory, we don’t recommend any specific oil brands. We always recommend using an oil grade recommended for your engine by the manufacturer and a brand that fits your budget. But beyond that, we find that brand makes very little difference. If there were an oil that consistently out-performed the rest of them, we’d have no reason to keep that information secret, but we just haven’t found that oil yet. 

You can go into any mass retailer (Wal-Mart, Meijer, AutoZone, etc.) and buy a 5W/30 (or any other grade) that will perform well in your engine. One of the best-kept secrets of the oil industry is that these store brands are actually the same, quality oils that are produced by the major oil companies. The only difference between these products and the major company brands is the name on the container and the price. Don’t believe us? Try running your own experiment: do a sample on Oil A after a known number of miles, then do a sample on Oil B and compare the wear levels. You may see a little fluctuation, but it’s very rare for one oil to make a significant difference in an engine’s wear patterns. 

But wait! We do actually have a preference when it comes to buying oils for our personal use engines. That preference however, has little to do with brand names. We tend to choose oil that does not contain sodium as an additive. Sodium is one of the markers for antifreeze contamination and when it’s present in the oil, that can make it harder to see coolant when it’s present. 

What about after-market additives? Some of them contain unusual compounds that can make it difficult for our analysts to determine if your engine has a mechanical problem. One such additive contains a lead-copper compound. Both lead and copper are metals common to bearing inserts. If you’re using an additive with lead and/or copper in it, it is difficult to tell whether those elements are coming from the additive or a problem with the bearings. There’s another potassium-boron-sodium compound that can mimic coolant contamination in testing. Some of these additives linger for a few oil changes too, so even if you haven’t used them recently, they might still be affecting your oil analysis results.

If you are interested in having your engine oil analyzed, you will receive a better analysis if you avoid oil and after-market additives that use elements we need to see clearly to do a thorough analysis. If you want to use an after-market additive, that’s fine, just let us know about it on the information slip provided with the sample.