API SM, SI and SJ motor oils are light duty oils

[1oldman]

Lubes'n'Greases July 2011 issue, page 17.

Page 22 from the July 2011 issue of Lubes'n'Greases:
"the days of a 'one size fits all' product my be numbered. In any case, the countdown to a possible GF-6 has begun in earnest."

[LeSabre in Buffalo]

GF-5 has just barely been fully rolled out. And, what with GM's dexos licensing/specifications being required on a lot of common GM cars now, it's likely coming to pass that one size fits all oils won't be as common. Turbos and direct injection can be pure murder on motor oils. Even some of GM's current DI V6's cannot go more than 5000 miles a change on full synthetics without the oil being useless.

GF-5 and API SN oils are darned stout, yet some engines manage to tear those oils apart in 5000 miles or less. Making a much stouter oil would be of benefit to the engine.

Really, SJ is better than what the L27's, S1 L67's and early SII L36's/L67's came with from the factory. The current SN oils should be massive overkill for engine protection, especially on a 3800 that's super-easy on oil.

[1oldman]

some of GM's current DI V6's cannot go more than 5000 miles a change on full synthetics without the oil being useless.

Wow! I didn't know that, but that is about right, I guess. The wife's CTS had oil changed at 9700. It's now just rolled over to 14K and the oil life monitor is at 33%. I did notice the life dropped dramatically while we were gone for 2 weeks and didn't drive the car. - BC

[LeSabre in Buffalo]

I'd change the oil in that 3.6 HF V6 sooner rather than later. The 3.0 version of the High Feature V6 is pure murder on full-synthetic oils, and can't go past 5000 miles on an oil change. GM had to re-calibrate the oil life monitors on some of the 2010 and 2011 Equinoxes and Terrains to compensate.

There's a good reason that anything older than GF-5 and API SN is light-duty. Fortunately a 3800 comes under light duty, and will run fine on those older-specification oils.

[CMNTMXR57]

Dexos required oils aren't just on "common" GM cars, it's for all of them by MY 2011 (MY 2010 in Europe).

The testing process/standards to receive the Dexos licensing is more stringent/harder than any current API testing process. It is meant to have one global standard for oil for all GM vehicles (except Duramax Diesels).

[LeSabre in Buffalo]

Dexos required oils aren't just on "common" GM cars, it's for all of them by MY 2011 (MY 2010 in Europe).

The testing process/standards to receive the Dexos licensing is more stringent/harder than any current API testing process. It is meant to have one global standard for oil for all GM vehicles (except Duramax Diesels).

With good reason. An oil analysis on my Cruze's 1.4 turbo on a 9000 mile run on Quaker State's full synthetic dexos1 offering showed that it beat the oil to heck. The oil life monitor indicated 10% life left. I can't imagine how many folks will run that OLM down to 0%, and be surprised in a few years.

[BonneMe]

The problem with modern direct injection engines is the high fuel wash that goes down the cylinder into the oil. The higher concentration of fuel in the oil makes it break down much faster. On VW/Audi DI engines N/A and Turbo, the longest oil can go before breaking down a lot is around 5,000 miles.



Dexos certs have been criticized as a bit of a licensing line of profit... I think manufacturers should work together or get API in gear and make an easier, stronger, and better standard with more info for customers. Too much in the oil discussions in car enthusiast forums is hearsay and guess work. Facts are very scarce.

[CMNTMXR57]

Dexos required oils aren't just on "common" GM cars, it's for all of them by MY 2011 (MY 2010 in Europe).

The testing process/standards to receive the Dexos licensing is more stringent/harder than any current API testing process. It is meant to have one global standard for oil for all GM vehicles (except Duramax Diesels).

With good reason. An oil analysis on my Cruze's 1.4 turbo on a 9000 mile run on Quaker State's full synthetic dexos1 offering showed that it beat the oil to heck. The oil life monitor indicated 10% life left. I can't imagine how many folks will run that OLM down to 0%, and be surprised in a few years.

How much of that is from the turbo though? Any oil, Dexos certified or not, is probably not going to fair well in terms of useful life left in it with 9k on it.

[LeSabre in Buffalo]

The turbo might have something to do with it. Also being a timing chained VVT DOHC engine with separate cam phasers for intake and exhaust cams. Lots of oil-actuated and lubricated stuff to beat up on the oil. I'm frankly thrilled that the oil is merely beat to heck and needing to be changed at 9k miles, and not totally useless black sludge.

It may well be the oil life monitor needs to be taken with a grain of salt. GM's historically made very accurate oil life monitors. It could be these aren't quite as accurate out in the real world as they are in the lab.

[1oldman]

Dexos required oils aren't just on "common" GM cars, it's for all of them by MY 2011 (MY 2010 in Europe).

The testing process/standards to receive the Dexos licensing is more stringent/harder than any current API testing process. It is meant to have one global standard for oil for all GM vehicles (except Duramax Diesels).

With good reason. An oil analysis on my Cruze's 1.4 turbo on a 9000 mile run on Quaker State's full synthetic dexos1 offering showed that it beat the oil to heck. The oil life monitor indicated 10% life left. I can't imagine how many folks will run that OLM down to 0%, and be surprised in a few years.

I think GM would like the oil changed at 20% life on the oil monitor. Cadillac will do it for "free" when the monitor is at 20%. - BC