History lesson- 20w-20 motor oil

[Kestas]

quote:

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Originally posted by buster:
So why did they go back to 40wts if 20wts were used in the 40's?

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Because underhood temperatures have increased dramatically since the 40's.... so much that 20W oils would suffer from volatility loss. The modern 20W oils are synthetic because only synthetic can withstand the temperatures and prevent loss from volatility.

 

[Blue99]

quote:

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Originally posted by G-Man II:

quote:

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Originally posted by Blue99:
So today, a 20W-20 at -10C/14F is the viscosity equivalent of a very good 5W-30 rating of 4250 at -30C/-22F.

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You are so wrong it's not even funny.

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My comment was not intended to amuse or not amuse you, G-Man, as it is simply based on lubricant cold temperature viscosity properties.

Fact - At cold temperatures, dynamic viscosity for a dino oil increases by a factor of 2 for every 5C temperature change, synthetic oils increase by a 1.7 factor.

Using simple math, backing up with the factor of 2, a 20W rated at 9500 cP @ -15C/5F would be 4750 cP @ -10C/14F.

Fact - 4750 cP @ -30C is a very good cold crank rating for a typical 5W-30.

So the factual analogy is that a 20W-20 with 4750 cP at -10C/14F is the same dynamic(resistence to pumping) viscosity at 14F as a 5W-30 rated 4750 cP @ -30C is at -30C/-22F

4750 cP is 4750 cP regardless of temperature.

Also note, the ConocoPhillips 20W-20 mentioned above is listed on the data sheet as 3493 cP @ -15C/5F.

This is a clear indication that a 20W-20 has cold start performance at 15F or 10F, certainly below the 20F temp per your post.

 

[G-MAN]

quote:

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Originally posted by Blue99:

quote:

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Originally posted by G-Man II:

quote:

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Originally posted by Blue99:
So today, a 20W-20 at -10C/14F is the viscosity equivalent of a very good 5W-30 rating of 4250 at -30C/-22F.

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You are so wrong it's not even funny.

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So the factual analogy is that a 20W-20 with 4750 cP at -10C/14F is the same dynamic(resistence to pumping) viscosity at 14F as a 5W-30 rated 4750 cP @ -30C is at -30C/-22F

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I thought you were saying that a 20w20 "today" (i.e, a modern 20w20) is the equivalent of a 5w30 when BOTH are at -30C.

Given your further clarification, I can see your point.

 

[jorton]

So I don't think I should put SF in my 99.

 

[Jimbo]

quote:

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Originally posted by TallPaul:

quote:

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Originally posted by Chris142:
Funny how this thread showed up today. I was at Carquest this morning and they have 5 qts of Pennz 20w-20 on the shelf.

It's very dusty, faded and rated "SF".

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Buy them. They could become collector's items.

I just bought a can ot 10w30 Veedol rated API Service MS DG DM. That predates the S designations. Wonder how old that would be?

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I think the MS rating started in 1964.

MS = Motor Severe [gasoline]
DG = Diesel General
DM = Diesel Moderate

 

[Jimbo]

quote:

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Originally posted by Ugly3:
Just keep in mind the number of "loose" engines that ran on 20W oils in the old days. Those 20W oils were not up to par with the 20W oils of today. Why are we concerned about a new engine being speced for a 20W oil?

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How long did a typical car last in the 1950's before being junked, or at least needed internal engine work, 60k miles? OCI's were in the 1-2k miles range as well. We expect about three times the service life on one third the rate of oil changes today. It was the elevated temperatures of emissions controls that led to thicker oil specs in the 1970's, but it seems that average engine life also took an upturn at the same time. Granted, with modern oil chemistry, we can go thinner again without going back to 60k mile engine life.

On the topic of pour points, SA-rated straight 30 (Coastal) was hard, like rubber, at 0F in my freezer test. You could actually see the wax crystals in it.

 

[ikeepmychevytoo]

Umph...

OK... I'm considering to use it this summer (phew.. said it). I searched and found this thread. To find a fresh bottle I may need to go some industrial site but I guess it'll be dirt cheap.

The funny thing is, it is among the recommended oils in my '84 v6 GM, and it perfectly fits my climate range yeararound, -5 to 34°C (23 to 93°F). On the manual it sits at the chart between 15w 40 and straight 30. It is recommended, as SF/CD rated, with 7500 mile OCIs!

So, I've been thinking on this for days and may be I dumbed myself, but why not? What would you do, would you try while we're entering the spring and save the first 0w 30 GLX for the winter (to better see if there is difference). Per the manual it fits the bill perfect. Visc. @ 100°C is ~8.9, looks low but while the 5w 30 isn't allowed above 100°F, 20w 20 is allowed! It states "Lower viscosity engine oils can provide better fuel economy; however, higher temperature weather conditions require higher viscosity engine oils for statisfactory lubrication"

What would be the worst case scenario for 3000 mile before drain? Right now in the crankcase is Havoline 5w 40 synth.

 

[Propflux01]

I thought the 'MS' was "Military Spec"..????

 

[addyguy]

In light of G-MAN's success with 20W in his car, I thought I'd bring this thread back, as many are doing.

Modern, group II made 20 weight oils probably have almost the same abilities as a 5W-20, so you could run this grade year-round in a lot of areas of NA.

TallPaul was mentioning that Valvoline has stopped making 20W oil...its a shame this is happeneing when it seems to be a quality product...

 

[TallPaul]

They told me no more Premium Conventional 20w (even though their prod data sheet shows it), but that the All Fleet still comes in 20w and that is even better as it will have HDMO levels of zddp.

 

[bithebay87]

Remember running this til maybe 15 years ago tops.
Gramps ran Mopar 2-250+k and new one. 225's and many 318's. Millions of accumulated always qagb 20w20, or hdx.
We had cases in the shop for years
I would run a 20w-20 still today.


-harvey

 

[OilUzer]

The only good thing about straight 20 is no vii I assume.
Other than that, it is still as bad as 2005 or early 1970's

 

[FCD]

Never seen 20W-20, but a couple brands of 20W-40 PCMO are sold here in Spain, ancient Group I , API SF stuff.

 

[farrarfan1]

Wow, a 15 year old thread resurrection. Wonder what the record is.

 

[mpack88]

If you look at the dates it cam back up several times. Originally 7/31/05, then 2006, 2008, now 2020.

 

[wwillson]

No idea what the record is, but it would be best to start a new thread

 

[nascarnation]

Back in the late 60s one of my fraternity bros got big discounts at D-A Lubricants in Indianapolis.
I got many quarts of 20w20 from him and used it in small block Chevys with much success.
Don't know what the low temp vis was, but it cranked pretty good in those Michigan winters.

 

[ZeeOSix]

Is 20W-20 even sold these days?

 

[53' Stude]

Originally Posted by ZeeOSix
Is 20W-20 even sold these days?


Actually I saw a 2gallon container at Rural King for $24~

Was non detergent also and they carry SAE 30and 40 non detergent.

 

[bbhero]

Originally Posted by wwillson
No idea what the record is, but it would be best to start a new thread



I see what you are saying...

But I actually like seeing a really old thread brought back up... Because it is a reminder that certain conversations/topics have not really changed a whole lot in this entire time frame. . . And it is interesting to read older historical posts of what other members thought about this topic 15+ years ago. It provides a insight into how things may have or have not changed.