Oil viscosity - more difference than I would have thought

[theholycow]

I don't have time to read the whole thing right now but I do want to skim it...

Absent this, play it safe and follow the severe service interval specified in the owners manual. - I disagree with that blanket statement. I would have said to follow the owner's manual, whether you qualify for severe service or regular.

3000 mile myth section: Agreed. Also, that's interesting about those Saturns.

You'll often see claims such as "everyone falls into the severe service category," but these claims are untrue - Agreed.

For example, the U.S. and Canada has fuel with high sulphur levels which can cause more oil contamination. Japanese fuel has very low sulphur levels. Europe is in-between. - Wait, there's sulfur in gasoline? I thought it was only in diesel and was refined out of gasoline.

The dealers also offer a time guarantee, generally that they'll get you in and out in less than 30 minutes or the next oil change is on them. - Around here, a dealer oil change has always meant waiting two or three hours when I've tried it.

SAE30 oil. Some quick-lube places have been known to offer advertised specials that use SAE 30 oil, as opposed to 5W30 or 10W30. - LOL WUT? I've never heard of any shop putting in SAE 30. In fact, I can't even find SAE 30 if I want it, though I haven't tried hard.

5. Selling overpriced, and often low quality, parts such as wiper blades and washer fluid, PCV valves, thermostats, etc. Never let a quick-lube place do any mechanical work on your vehicle.. They do no use journeyman mechanics.

6. Using poor quality filters. You really want to bring your own filter, from the dealer, with you when you go to a quick-lube place. They may take $1 or $2 off the price if you do this but don't count on it.
....ok then. I think even the pimply faced teenagers working there can handle installing wipers, and most filters are fine.

The reason that oil viscosities have gotten thinner is because bearing clearances have become smaller. Using thicker oils will interfere with oil flow and the oil pressure will increase. - Agreed.

Oil Analysis comments throughout: I don't disagree.

Aftermarket Filters - Uhh...he lists AC/Delco and Motorcraft. I thought those were GM and Ford OE.

[bowtieguy]

Originally Posted by SentraSE-R

What do you disagree with, and why? Your link's author seems logical and factual to me.

"seems" is a key word there. are you being confrontational, naive, or just plain uninformed?

HC touched on a few of my points, but this one baffles me..."Synthetic oil is a good choice if you have a high performance engine or if you live in an extremely cold climate, otherwise it provides no benefit (but no harm either)."

really? what about extremely warm climates? what about the occasional collant issues(busted hose, water pump failure, etc.)? what about the benefit of "extra" extended change interval, since he advocates extending conventional oil changes.

oil analysis...hmm, expensive, and based on a very small portion. i'll pass. he also recommends OE filters, then claims quality aftermarket is alright. make up my mind.

so, i'll continue to use synthetics, saving more money(and time), being more green, and getting better lube than conventional users...PERIOD

that's based on research(both intellectual and hands on) as well as my own experiences and observations.

[add|ct]

It seems like that article was written late 90s to me, though. So, it may have been more accurate in certain areas than others. Good write up, still.

[theholycow]

Originally Posted by bowtieguy

so, i'll continue to use synthetics, saving more money(and time), being more green, and getting better lube than conventional users...PERIOD

that's based on research(both intellectual and hands on) as well as my own experiences and observations.

I have no doubt that you have experience showing long-term survival of engines with synthetic, but what experience do you have of sub-par performance from dinosaur juice when used as directed?

[shatto]

For one thing; he contends there is practically no difference between using synthetic and dino oil.

I contend that the synthetic oil from my Tundra with 30,000 miles already on it will allow less wear than new dino oil if put into an engine and run another 25,000 miles and checked by oil analysis. Oops, can't do that...let's just use the 'rated' life of the dino oil.

[add|ct]

I didn't take from this person that he was against synthetics. In fact, synthetics have improved drastically since he did this write up.

[shatto]

Originally Posted by add|ct

I didn't take from this person that he was against synthetics. In fact, synthetics have improved drastically since he did this write up.

Yup.

[FrugalFloyd]

Good points about the article, HC. I didn't read it critically, and missed them. My car interest waned in the 90s, though, so I'm probably in the same mindset as the author.

On a related note, Toyota put out a TSB saying its official recommendation for oil lowered viscosity from 0W-30W for my car to 0W-20W. It specifically did NOT recommend 0W-20W for most of its pre-2006 engines, or any of its pre-2005 engines, IIRC, and warned of possible engine damage with the combination of thinner viscosity oil in older engines. I suspect that's because of closer bearing tolerances in 6006 and newer engines. Those of you putting 0W-20W in older cars (of any make) are taking an unnecessary risk, based on my understanding of Toyota's TSB

[add|ct]

...which doesn't make any sense. Isn't 0w-30 better than 0w-20 if your call is supposed to take 30?

[trollbait]

a true synthetic 0w30 is just as good at start-up as 0w20

It may not make a difference in practice, but the measured viscosity is thinner in the 20 than the 30. That's also true of 5wx oils, not just the 0wx ones. The gap between two different viscosity oils is greater at cold temps than at operating temps. If you can find published cold viscosity measurements for an oil, keep in mind, the standard test for that number is at 94F. So, at what most think of as cold, the gap will be wider.