A look at that new engine oil

April 1, 2011 | By Richard Prince


I immediately thought of you when I heard about the new engine oil rating and products.

It’s the rating GF-5 or, as applied to GM-specific products, “Dexos 1.” It is supposed to protect, clean, and reduce engine emissions better than previous oils (synthetic and/or conventional) and is claimed to be good for older engines.

OK, is it good for “our” older engines that could be up to 100+ years old and have flat tappets?

Could this end the “flat tappet & ZDDP” controversy forever? It’s interesting at the least.


Way back in the good old days the primary function of engine oil, by far, was to protect engines from rapid wear.

Over time, by virtue of inventions like the thresher, which eliminated the laborious need to separate the grain from the stalks and husks by hand, and the computer, which eliminated the laborious need to think independently, all those trillions of hours that were saved could be put to other uses.

For some, all that spare time has been devoted to dreaming up new motor oil formulations that satisfy new goals for motor oil.

As I understand it, there are three primary factors that drove GM’s decision to establish a new oil standard.

The first, of course, is money. By creating two standards, one for gasoline and the other for diesel-powered engines, that together apply to every vehicle GM makes, they reduce lots of costs associated with multiple standards, such as costs tied to maintaining inventories, distribution, procurement, testing and so on. GM will also make a lot of money from licensing because in order to sell product labeled as meeting the new GM standard, oil companies will have to pay GM a licensing fee.

A second important goal for this new oil is to increase fuel economy. In very rudimentary terms, oil that provides a

higher level of lubrication will help fuel economy by reducing internal engine friction. Similarly, oil that is less viscous will help fuel economy because it will consume less of the engine’s power to move around inside of the engine and as engine parts interact with it. This is why we see widespread use of lightweight engine oils today that didn’t even exist a generation ago.

A third factor behind the creation of the new oil standard is environmental concern. Oils meeting the new standard are supposed to last longer and therefore recommended oil change intervals can be extended. Oils that last longer conserve limited resources and reduce the costs and problems associated with recycling or disposing of waste oil.

The new oil specification also addresses environmental concerns by substituting certain less-environmentally-offensive ingredients for the current more-environmentally-offensive ones.

One such substitute that pertains to your question about flat tappets and ZDDP is the inclusion of molybdenum, a rare and very expensive trace element that will substitute for zinc as an antiwear component.

Will molybdenum provide good protection for flat tappets in old engines? Probably, but without valid testing or enough long-term statistical data, nobody can say for sure.

And, not surprisingly, nobody has actually tested the effectiveness of oil meeting the new specification in antique engines and neither GM nor the oil companies intend to at this point.