Engine oils test results.

Ten years old = obsolete.

Do you think today there is a big difference between brands and these differences did not exist 10 years ago? Based on what?

The manufacturers specification for motor oil have changed drastically in the last decade.

To say that one should just buy the cheapest API rated oil that meets the manufacturers viscosity requirements is asking for trouble.

Not is someone is driving a 10-year old car, right ? ;-)

That's OK, I long ago concluded that there's no significant difference between what Consumer Reports prints and what a room of monkeys pounding typewriters prints.

Buy THAT on price.

At the end of this thread the above statement will be the only one with any significance. The real world and CR seldom coexist.

The problem with that "study" is that they used taxi's which run pretty much all the time and roll up miles very fast. As a result they don't have nearly as many temperature cycles (warm up,cool down) as a normally driven car would. So they don't get nearly the amount of soot, sludge, etc that is one of the things oils have to protect against. I believe the study is valid if you own/operate a taxi.

Several years ago, John M. Feiereisen, a designer of oil additive packages, regularly mentioned that he bought the cheapest motor oil with the highest API quality rating available. I believe the highest API grade for gasoline engines back then was SH or SJ.

But 10 years prior to that evaluation, CR did another, much less extensive one, of API SF grade oils, where they tested only viscosity, and they found that only 1 brand 10W-40 maintained sufficient viscosty (Castrol, which claimed it maintained viscosity better than others). I believe most 5W-30 oils failed while most 10W-30 oils passed. This roughly corresponded to GM's findings at the time, where they found most 10W-30s to be adequate but failed all 10W-40s. I doubt that monkeys typing randomly would agree with GM's findings.

That may not be a good idea, anymore, if you drive an older car. Some of the newer API certifications actually have reduced levels of anti-wear additives for emissions reasons.

Personally, I just run "fleet" oils (both Diesel and gasoline rated) in my older cars. It's usually less expensive than generic gasoline-only engine oil and has higher levels of both anti-wear additives and detergents.

nate

I quit paying attention to CW reports after they rated the Corvette as "Poor" for body corrosion......Hello?....fiberglass....

These fiberglass panels are attached to metal parts. Maybe these metal parts do not hold well... ?

I remember seeing such problems in old Germany car "trabant" which also had fiberglass panels - the problem was that everything else rusted out and the panels did not hold :-)

do_not_spam snipped-for-privacy@my-deja.com wrote: This

AT THAT TIME, 10W-40 oils failed all automaker tests because of slude and varnish accumulation. Again, at that time, any oil that had the huge variation between cold and hot viscosity would have a huge buildup of junk in the engine. STP used to make a 10W-50 oil and it failed worse than others.

I remember the article referencing the GM statement mentioned higher deposit levels on the piston rings when 10W-40 was used. It also said

I also remember several brands of SE-rated 10W-50 oil in the 1970s, including Phillips Trop Arctic, some of them advertised as being good for 15,000 miles (not synthetic).

CR often does not know what they're talking about. The have a bunch of housewives rating products they know nothing about.

I do remember years ago CR rating the "King of Sludge formation"-Castrol as the best oil. Funny thing about this is that Castrol isn't really an oil, it's an label since they're likely to buy it from several different sources a month, and have not the ability to formulate it's base.

MB

I have some issues with Consumer Reports, especially their automotive reviews. Granted, I haven't picked one up in 5 years or so, but at the time that I was reading them I could sit and pick apart their comparisons and show how they seemed to judge based on opinion, uninformation, unproven and/or made up data, along with comparing vehicles that are not even in the same category.

YMMV.

Consumer Reports employs many automotive engineers, and I assume they handled the technical aspects of their oil evaluation. But at least the vast majority of them have been male, so they would have to be househusbands.

For their late 1980s article they tested 10 different 10W-40 oils, and of them, only Castrol GTX Multigrade maintained SAE 40 viscosity at 100 Celcius after being sheared several times through a diesel fuel injector. The next closest were Pennzoil Multivis With Z-7 and Texaco Havoline, which dropped to just below 40 weight. The Castrol also showed the smallest drop in hot viscosity, not only for their 10W-40 but also their 10W-30 (but Pennzoil 10W-30 came close). CR admitted that their testing was very limited for this review, but they did also mention that 2 oils failed a cold test. No sludge testing was done, but for their 1996 test (oils were SH grade rather than SF) they found no significant differences in sludge buildup.

Do you have any test results, or even evidence of what quantity of additives Lubrizol has sold to Castrol per quart of oil?

Its original panels were cotton or cellulose fiber reinforced with phenol resin, and soon after the fall of the Berlin Wall, a news report showed a Trabant sitting horizontally in a dumpster. It was a nearly perfect fit.

Correct. Having been an audiophile some years back I remember their recommendation for a budget cascette deck (no one uses them anymore of course) and they based it soley on features not quality. The recommended the hapless Aiwa because it had a bunch of useless features and at $200 (at the time) anyone who knew anything would tell you that the Yamaha was a better $200 deck becuase like the higher models in the line it used the same sendust head and had few creature features but tremendous quality at that price point, which is what anyone would have been looking for.

This was the first time (probably around 1984) that I realized that one should listen to people who know, not a general panel trying to rate a broad range of products as is CR. An example of this would be looking at their recommendation for a washer and/or dryer and actually talking to sales/repair people at Sears/Lowes/ Home Cheap-0 and you'll see that the latter group have much more REAL LIFE experience and will come up with a different recommendation.

MB

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