Pennzoil Platinum Euro L 5W-30 Volatility Results - Dec 2024

[JAG]

The oil was tested alongside Quaker State 5W-40 API SP, which is believed to have a Noack volatility of 5.7%. The temperature was set to what appears to be ~420 F on the oven's dial. A thermocouple reading on a separate oil at that setting was 431 F. PP Euro L 5W-30's volatility impressed me. I was expecting higher volatility than it has. I knew its Noack must be < 10% due to meeting MB 229.51 specification. My Noack estimate at 2 hours is considerably less than 10%. After you see the graphs, you'll see that it is obviously higher than QS 5W-40's 5.7%.

Between hours 2 and 3, PP's volatility did spike and it is NOT due to measurement error. I zero the scale, weigh one oil, then the other, zero the scale again, weigh both oils, etc. I weighed the oils 4 times at hour 3, and averaged the weights. PP's weights at hour 3 were 6.5125, 6.5125, 6.5125, and 6.5175. That is excellent repeatability. I do think the volatility spike is real. After hour 3, its volatility settled down again, but the effect of that earlier spike remains in the cumulative weight loss.

 

[JavierH19]

Expected but negligible. Both oils are great. Thank you for the results.

 

[Jetronic]

what's interesting to me, is that the evaporation never seems to taper off, so it's not just the light fractions evaporating, or there are a lot of them.

 

[JAG]

I found that interesting too, Jetronic. The oil that I most evaporated was Quaker State 0W-20 Ultimate Protection. It lost 31.5% of its weight and its evaporation rate was similar to what it was earlier. See the graph below. In that test, the temperature was increased several times early on and you can see it in the slope of the cumulative weight loss curve. If I had never done these tests, I would probably expect a tapering off of volatility not just due to lighter fractions evaporating off but also by oxidation enlarging base oil molecules, making them less volatile. It is fun to do tests because one can get to the truth rather than relying on just theory.

 

[JAG]

This is what the oils look like after 5 hours. The cups are tilted. The oils are very dark. Copper cylinders that you can see await getting put in the oils and being heated to 220 F to see how much the oils tarnish or corrode the copper.

 

[Sandstorm]

I suggest that you include error bars and standard deviations in your graphs

 

[Rand]

whats going on with these 2 graphs labeled the same?
Also since oils aren't tested at temperatures seen in normal engine use what validity does this have?

 

[JAG]

I suggest that you include error bars and standard deviations in your graphs

I would do that if it were straightforward to do in an honest way.

 

[JAG]

Rand, good catch. The second graph in the first post had incorrect labels. I have updated it. The second graph is the ratio of cumulative mass losses of PP to QS as a function of time.

About the temperature...I stole this image from buster. There are multiple studies of temperature of the oil in the ring packs. Noack test temperature is 250 C = 482 F.

 

[Danno]

Also since oils aren't tested at temperatures seen in normal engine use what validity does this have?

Oil side of piston rings and underside of pistons could see those temps.

 

[dubber09]

Do oils made "from/with natural gas" evaporate easier? Logic says they should.

 

[OVERKILL]

Do oils made "from/with natural gas" evaporate easier? Logic says they should.

Why? It's just a group III base oil. The GTL base oils actually have very low Noack relative to their peers, but it's not uncommon for the ones used to be thin, which are going to be more volatile.

 

[Rand]

Oil side of piston rings and underside of pistons could see those temps.

Right I asked because I felt it should be included.( along with the graph axis correction)

 

[JAG]

Do oils made "from/with natural gas" evaporate easier? Logic says they should.

Gas-to-liquid (GTL) oils tend to have very low volatility because they have a narrow size distribution compared to regular Group III. Their volatility is similar to PAO of the same viscosity.

GTL is made from natural gas, but it no longer has natural gas properties. Like if you eat chicken, you don’t become a chicken.

 

[JAG]

After the 5 hours of the volatility test, the copper cylinders were added. Prior to that, I rubbed sandpaper on them so they had no corrosion. The cylinders were fully coated in oil but the oil level went up to about halfway. First, the oils were heated to ~200 F for 30 minutes. No tarnishing or corrosion was seen. Then they were heated to ~230 F for 30 minutes. Still no change. Then I heated them to ~ 275 F for 30 minutes. Then some mild tarnishing could be seen. Neither oil attacked the copper like I was expecting considering the abuse the oils had suffered. I have seen heated motor oils turn copper black and also even virgin oils leach enough copper to darken the oil around it. In the PP’s copper cylinder’s ends, you can see the part that was above and the other part that was below the oil line. On QS’s cylinder’s ends the tarnish is darker and more uniform. On the circular part of the cylinders, QS’s copper looks slightly less tarnished. PP’s copper has almost a red Kool-Aid color there. The particles you can see in the PP cup are soft agglomerations due to oxidation (not good). QS did much better in that regard but this was not a deposit test. It is worth noting though.

 

[JAG]

Here are some examples from past tests with entirely different test conditions. The first image shows the copper leaching that a virgin oil did within seconds of being at high temperature. Saw it happen in real time which was pretty wild. Took the photo after letting the oil cool. The dissolved copper was still floating near the copper cylinder since it didn’t have time to fully disperse.

The other photo shows a copper cylinder that is black on roughly half of it.