Conventional oil vs synthetic oil question

[yelbike]

That's one explanation.

Let us know how your test to prove this goes.

By the way, I highly doubt the synthetic oil will have only 'slightly changed color' after 5,000 km particularly in a diesel. I use synthetic in my NH TC25D and it turns dark after only a few hours.

How will you be quantifying the results? Filtering out the contaminants some how?

I was referring to a gas truck, I realize diesels engines discolor the oil very quickly.

The results maybe more apparent with less mileage, maybe only 1000 miles

 

[MikePA]

The results maybe more apparent with less mileage, maybe only 1000 miles

Good. Your tests won't take as long.

I'll be interested in your results. Please post pictures of the oil.

 

[Z71]

The additives used in the oil can also cause it to darken during normal use.

 

[kenmac]

The reason the oil is darker is, because the dino oil can't handle the heat. The oil breaks down and turns the oil dark

 

[BarnieTrk]

If the darkening was the result of residual puddling contaminating the new incoming oil, it would be the same with either oil, assuming the same drain time/porcedures were being used.

I'll bet someone with access to a professional OIL ANALYSIS service could likely tell us all what is the deal with the relatively 'new' dino oil darkening up so quickly.............

BarnieTrk

 

[xring100]

The reason the oil is darker is, because the dino oil can't handle the heat. The oil breaks down and turns the oil dark

Yes you are correct its an oxidation reduction reaction that breaks the carbon carbon bonds in the oil and thus causes the black color. In college i worked in GM's material lab. We tested many oils from various suppliers using. PDSC - Pressure Differential Scanning Calorimetry. The oil sample was put in a clean tin and pressuresized with oxygen at high pressure and temperature which were maintained. Dino oils usually broke down in a mater of hours indicated by spike in temperature as the bonds broke. They would come out black. We ran synthetic mobil 1 it ran all weekend, aborted the test and inspected the sample it had not broken down.

In real world as others mentioned even synthetics still come out brown after several thousand miles as they've picked up contaminants from combustion gases etc. You still have an oil that is still lubricating. I run Mobil 1 or AMSOIL in all my newer engine's.
GM 3800 in our granprix hated AMSOil it burned it and caused lifter noises. Mobil 1 was better but it never stopped burning oil after the AMSOIL i put in at 56,000 miles. It is the only time ive ever had a problem with AMSOIL. Buddies 04 3800 Lesabre did the same thing.

 

[Copperhead]

Getting close to the less than 10% mark on the OLM on my 2013 Silverado. I generally did oil changes at around 6000 miles on it, but for my own curiosity I decided to go full length on the OLM and send in a sample. It should be almost at 7500 miles on the oil when the OLM gets below 10%. It has been on Schaeffer 9003D 5w30 synthetic. I get oil sample kits and analysis for free from them since I order large quantities of oil for my commercial needs, and am going to send one in on this oil when I change it soon. It is darker, for sure, than out of the container. But Schaeffer already has a dark tint of green due to the add pack in the oil. It hasn't darkened much from that basic tint. Will be fun to see the used oil sample results.

 

[yelbike]

Yes you are correct its an oxidation reduction reaction that breaks the carbon carbon bonds in the oil and thus causes the black color. In college i worked in GM's material lab. We tested many oils from various suppliers using. PDSC - Pressure Differential Scanning Calorimetry. The oil sample was put in a clean tin and pressuresized with oxygen at high pressure and temperature which were maintained. Dino oils usually broke down in a mater of hours indicated by spike in temperature as the bonds broke. They would come out black. We ran synthetic mobil 1 it ran all weekend, aborted the test and inspected the sample it had not broken down.

In real world as others mentioned even synthetics still come out brown after several thousand miles as they've picked up contaminants from combustion gases etc. You still have an oil that is still lubricating. I run Mobil 1 or AMSOIL in all my newer engine's.
GM 3800 in our granprix hated AMSOil it burned it and caused lifter noises. Mobil 1 was better but it never stopped burning oil after the AMSOIL i put in at 56,000 miles. It is the only time ive ever had a problem with AMSOIL. Buddies 04 3800 Lesabre did the same thing.

I get from this than, for a non scientific experiment, if I was to put two open oil samples in tin containers, placed them in the oven, bake for some time at a high enough temperature, the dino oil would darken first?

That would be an interesting test for than the darkening would attributed to breakdown rather than the contaminates in suspension.

 

[MikePA]

I
That would be an interesting test for than the darkening would attributed to breakdown rather than the contaminates in suspension.

Let us know if this test proves your hypotheses. Shouldn't take very long.

 

[yelbike]

Let us know if this test proves your hypotheses. Shouldn't take very long.

I'm not going to actually do this test, I think the fire hazard is just to high.