A Comparison of 20 and 30 Weight Oils - Part 2

[OldCowboy]

I decided to expand my analysis of wear levels demonstrated by 30 weight vs 20 weight oils in an attempt to gain greater analytical rigor.

It seems inappropriate to lump 4, 6, and 8 cylinder engines in the same analysis. So I will be reporting on each of these engine classes separately.

Additionally:
- There is only one reported sample for an OP/engine/oil combination
- Samples that had mixed weights or had additives were not considered
- Samples from engines with less than 20,000 total miles were not considered
- Samples that did not have iron as the highest wear metal were not considered
- Samples that had significant fuel or water contamination were not considered
- An attempt was made to select a balanced mix of manufacturers and engines

Here are the results for 4 cylinder engines. 30 weight oils are presented first.

Here is the 20 weight oil data.

With this more extensive, robust analysis, it can be seen that the 20 weight oils show marginally better results for Fe, Cr, Cu, Pb, and Sn. The 30 weight oils show marginally better results for Ni and Al. That being said, neither group of oil samples is statistically different than the other. This casts doubt on the "known" superiority of 30 weight oils, at least with these 4 cylinder engines.

 

[pbm]

That's a very interesting compilation of information and I appreciate your efforts.
It's interesting that the Toyota 1.8 (which I have in my Corolla) did so well on Syntec 5W30 especially at a 13.5K OCI.

 

[oggb]

Thanks very much for putting the time and effort into doing this. Very neat.

 

[Y_K]

SWRI has interesting viscosity to wear graphs. Statistically valid, made in real time on the same type of engines for the same amount of time.

 

[Artem]

Part 2 is always better. Good job OP, i really appreciate the efforts and thanks for including my UOA... twice!

Seems that the w20 is going a good job at protecting engines. (of course i never doubted this, since if it wasn't working, auto manufacturers wouldn't be recommending it) I will wait and see where the thin oil trend goes in the next few years and once these engines rack up 200k+

 

[tig1]

Originally Posted By: Artem
Part 2 is always better. Good job OP, i really appreciate the efforts and thanks for including my UOA... twice!

Seems that the w20 is going a good job at protecting engines. (of course i never doubted this, since if it wasn't working, auto manufacturers wouldn't be recommending it) I will wait and see where the thin oil trend goes in the next few years and once these engines rack up 200k+


I used M1 5-20 33 years ago in engines normally using 10-40 and 5-30. I never had any wear problems then and don't expect any now. Only thing back then my slant 6 dodge truck engine used a little more oil with the 5-20

 

[Artem]

Tig, you throw that "33 years" phrase around so much, you should include it in your Sig.

I don't know where you found 5w20 oil 33 freakin years ago. Do explain.

 

[tig1]

33 years is a long time using one branded oil. It's historical. As for M1 5-20, it first came out in 1974 in the US. See, you just learned something.

 

[Doug Hillary]

Hi,
Artem - M1 5W-20 was introduced in 1974 - 37 years ago

5W-20 viscosity mineral lubricants were used briefly in Germany in the 1970s

 

[Steve S]

I used M1 5w20 oil in my 74 chev pickup in who would have guesses it in 1974 and the mobil gas station I did busisness with sold it for around $3.50 per qt.I tried All Proof and Eon The first syn oil I used was in my 1967 Yamaha 125. Steen C chemical kubricant. The around 1979 M1 was a 5w-30. Around 1995 I quit my general use of syn oil because of the engines I got into a work looked so good with the Hyro treated oils.

 

[Steve S]

Old cowboy is on fire!!!!

 

[buildtopic]

does it make sense to compare between 0Wxx, 5Wxx and 10Wxx ?

 

[Steve S]

I have used 5w-30 and 5w-20 in my cars which ever is cheaper at the oil change time even some 0w-30 at close out prices and I really haven't noticed much of any difference and to be honest it will not make any difference. Kinda like oil filters.

 

[crazyoildude]

strait 20 maybe but 5w20 33 years ago????

 

[OldCowboy]

Originally Posted By: buildtopic
does it make sense to compare between 0Wxx, 5Wxx and 10Wxx ?


0Wxx, 5Wxx and 10Wxx have the same viscosity at operating temp.

 

[Artem]

Originally Posted By: tig1
33 years is a long time using one branded oil. It's historical. As for M1 5-20, it first came out in 1974 in the US. See, you just learned something.
Originally Posted By: Doug Hillary
Hi,
Artem - M1 5W-20 was introduced in 1974 - 37 years ago

5W-20 viscosity mineral lubricants were used briefly in Germany in the 1970s


I was not aware that there were engines in the 70s that called for a 20 grade oil. I figured they all ran on thick juice.

So why did everything go back up to 5w30 or 10w30 and just now going back down into the 20s again??? There has to be some reason behind it.

 

[Doug Hillary]

Hi
Artem - Europe's most popular car in the 1950-1970s era - VW - used a 20W-20 lubricant. Many Euro engines (Ford, Volvo, Opel etc) used the same viscosity throughout Scandinavia and Germany for instance.

MB trucks (and some car models) used 10W-20 and 20W-20 HD lubricants and a 10W HD lubricant in temps below -14F. MB's OP readings were mandated on a 20W-20 lubricant

10W-30 which was introduced and became common in the early 1950s was a good "catch all" year round lubricant in most applications including those from NA.

20W-50 was developed for the BMC Mini with integrated gearbox/engine (one common lubricant)around 1958 by Duckhams (followed by Castrol soon after). It became a good? "catch all" too and promoted the use of higher viscosities - this was not intended!!!

The lightest recommeded viscosity for the application is typically the best overall performer

 

[jtaylor]

I think it's tough to compare the Redline and Motul type products' higher wear
#s to the more common oils' lower wear #s. This is an assumption, I know, but wouldn't one think that those drivers who deemed it necessary to add such premium ester based lubricants to their engines would probably, run them much harder, thereby increasing wear no matter which lubricant were used. I know I would run my engine harder with a better lubricant.

 

[tig1]

From about 1969 to about 1974 I used Valvoline HD straight 30 wt in the summer and HD 20 wt in the winter. That worked well for me at the time.

 

[tinmanSC]

Wow! Thank you so much for doing this. I was thinking of collecting data like this but found the task daunting. Thank you for putting in the time.