Best and the worst.

[OneEyeJack]

How much difference can there be between the best API cert PCMO and the worst? Should I restate the question? What is the difference between the cheapest API cert PCMO and the most expensive? Lets say we are talking about a 5k oci, moderate weather, never below freezing and never above 100F, 50/50 city/highway driving mix, late model family sedan with factory recommended service, other than the oci.

 

[tig1]

You may get hit hard for this question. BITOG can be a tough crowd. Good luck.

 

[OneEyeJack]

It's just a question. I read a lot of comments that amount to people putting forth their favorite oil. Is there any difference or given a reasonable selection criteria should you choose the one on sale?

 

[The_Jeff]

The worst is the stuff found to be below certified grade. One of the Carolina's Beaureau of Standards (not its real name) found Coastal 5w30 to be actually 10w30. And there was a fairly recent API bust of stuff not meeting SM, maybe someone remembers the link.

 

[gathermewool]

I tell all of my friends who change their oil every 3-5kmi to just buy what's on sale. For their mostly highway commutes it doesn't matter at all.

For other services or if some one was willing to extend their intervals, it DOES matter very much.

 

[HTSS_TR]

Originally Posted By: OneEyeJack
How much difference can there be between the best API cert PCMO and the worst? Should I restate the question? What is the difference between the cheapest API cert PCMO and the most expensive? Lets say we are talking about a 5k oci, moderate weather, never below freezing and never above 100F, 50/50 city/highway driving mix, late model family sedan with factory recommended service, other than the oci.

For 5-6k/6mo OCI in CA weather you just buy what is the cheapest SM dino. My +250k 17 year old LS400 had many different brands conventional and synthetic without any oil related problems. That car OCI with dino was 6-7k/6mo, with syn 12-14k/12mo.

If you have a car that is known to be a sludger, then you may reduce OCI to 4-5k/6mo with dino or 8-9k/12mo with syn.

 

[bodeh6]

Any modern oil whether dino, blend, or syn from a major brand (Valvoline, Castrol, Pennzoil, Quaker State, Mobil, Kendall, Motorcraft, etc) will have no problem with what you described.

 

[Spyder7]

Originally Posted By: OneEyeJack
How much difference can there be between the best API cert PCMO and the worst? Should I restate the question? What is the difference between the cheapest API cert PCMO and the most expensive? Lets say we are talking about a 5k oci, moderate weather, never below freezing and never above 100F, 50/50 city/highway driving mix, late model family sedan with factory recommended service, other than the oci.

Given the info above, and assuming the latest API spec is applied (SM), I would think very little. Not no difference, just very little difference for this type of usage.

-Spyder

 

[fdcg27]

It depends upon the engine, and it depends upon how it is used.
BMW, VW and Mercedes did not come up with their own oil specs just for grins, for example.
Another example is GM, which has two North American specs, in addition to its Euro specs, in addition to SM.
API SM is not sufficient for every engine sold in this country.
Now, if you drive a typical car in typical conditions, any API SM oil will do just fine.
If you drive a beast that is more demanding, API SM is not a sufficient spec.
The best API SM oils meet demanding manufacturer's specs, while the lesser SM oils don't.

 

[Pesca]

As long as you follow the manufacturer requirements (specific ratings), all rated oil will do OK in any modern engine. So yes, by what is on sale for a 5k miles OCI.

If you want what is best for YOUR engine (meaning your car with your driving style an pattern), then you will have to experiment to find the best for YOU.

But who need the best for your car, when doing OK will bring you to 2-300k miles easily, as long as maintenance is done properly?

 

[Spyder7]

Originally Posted By: fdcg27
It depends upon the engine, and it depends upon how it is used.
BMW, VW and Mercedes did not come up with their own oil specs just for grins, for example.
Another example is GM, which has two North American specs, in addition to its Euro specs, in addition to SM.
API SM is not sufficient for every engine sold in this country.
Now, if you drive a typical car in typical conditions, any API SM oil will do just fine.
If you drive a beast that is more demanding, API SM is not a sufficient spec.
The best API SM oils meet demanding manufacturer's specs, while the lesser SM oils don't.


I have a bad habit of stating "API" when what I should be stating, to convey the meaning that is meant, is the oil that meets the spec as required by the OEM.

My particular dinosaur only needs SJ, though I still stick to SM oils. I'm also fussy about them and am willing to tinker a bit to try and improve upon whatever I'm using (simply because I believe oils are generally blended to deliver the best they can at a given price point, rather than being blended to be the objectively best product the manufacturer can produce - after all, all oil producers are profit driven and the profit motive and "best possible product" are not necessarily synonymous).

I'm realistic enough to know that any improvement, either by choosing one SM oil over another, or even if (successfully) improving it slightly, its still only somewhat better than another product, and the "better" is for my application of it and may not be any better for someone else's needs.

-Spyder

 

[Spazdog]

Late model family sedan?

You could get away with using the cheapest API certified oil in a 3.0 Vulcan Ford just maintaining factory recommended OCIs but I wouldn't try that in a known sludger like the Chrysler 2.7 V6, Toyota 1MZ, or VW/Audi 1.8t.

I think VW specs a higher grade oil that is less prone to sludge formation.

I think the Chrysler just requires more frequent oil changes regardless of the quality of the oil. The 2.7 has a nasty reputation for sludge.

 

[Audi Junkie]

http://www.pqiamerica.com/testresults10W30April2010.html

 

[OneEyeJack]

So, one 5w30 oil that has an API cert is the same as another 5w30 oil with the same cert. The difference may be in additional manufacturer's spec's on the label, but if those are the same, too, then the oil is the same, right? The rest is marketing. The statement that Pennzoil causes sludge when another oil with exactly the same specs does not, makes this statement suspicious. Oil performance is as much additives as it is base stock. Without the additives the best base stock might not do the job at hand, that is lubricate the average family sedan.

 

[Spyder7]

Originally Posted By: OneEyeJack
So, one 5w30 oil that has an API cert is the same as another 5w30 oil with the same cert. The difference may be in additional manufacturer's spec's on the label, but if those are the same, too, then the oil is the same, right? The rest is marketing. The statement that Pennzoil causes sludge when another oil with exactly the same specs does not, makes this statement suspicious. Oil performance is as much additives as it is base stock. Without the additives the best base stock might not do the job at hand, that is lubricate the average family sedan.


Not the same. But the requirements to meet the API SM spec doesn't allow enough divergence between them for one to be objectively "good" while another is "bad." These days they're all pretty good. It just comes down to whether or not its worth spending any extra to choose one over the other. This is a good tool for making that decision (the PQI summary), but for the type usage you've described, you would be fine with any of them.

-Spyder

 

[mechtech2]

Best and worst indicate extremes.
And at the extremes, there are great differences.

Normally, name brand dinos are all excellent now, and getting even better.

But there are indeed lousy off brand oils - actually harmful for a bunch of reasons.

 

[Spyder7]

You may have a point there, as with the difference in price being as small as it is, the only off brand label I look at is Supertech. I like most of the brand names more, but for an off label, this one isn't bad.

-Spyder

 

[fdcg27]

Once again, it depends.
The Vulcan in our Aerostar would be happy with anything resembling oil, while the Hondas are only a little more picky.
The Subaru is a work in progress.
Some folks think it does better with a thicker oil, like GC.
Others have had used oil analysis on here showing good wear numbers in their NA Subies with thinner oils.
The BMW may be a little more picky, although when it was new, decent thinner grade oils were apparently not widely available here, so BMW speced really thick stuff, like 20W-50 down to 14 F.
It also depends upon how long you want to run the oil.
For a 6 mo/4-5K OCI, probably any API SM rated oil would do, even if the oil itself is either marginal or below spec.