Rotella Gas Truck - How Synthetic Is It?

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While I do not expect anyone to know exactly and though it is marketed as a "full synthetic", after 6 runs of it in my Rubicon (30K miles), I am leaning towards it being a "minimal" synthetic. No, I do not have any scientific data past my UOAs, but it has the same physical observed characteristics after a 5K run as the Mobil Super 5000 that I used in my 2010 FX4 for a number of runs. It is much darker than any of the other synthetics I have used (Castrol, Pennzoil, and Kendall), it produces some carbon flakes in the filter (just like MS5K did) and has somewhat of a burned smell to it.

Yes, naysayers, I know, far from scientific or convincing, but something tells me it has the bare minimum contents to be labeled a synthetic. Has anyone had a similar experience when comparing it to other oils or does anyone know what its composition is?
Fully Synthetic is full synthetic. There is no minimal synthetic. The bare min contents for a synthetic oil is 100% synthetic oil

Semi synthetic is a mixture of conventional and synthetic.
 
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You already made your observation, formed a hypothesis about what the issue might be, and then point to any anecdotal evidence (because it's certainly not scientific) to confirm your hypothesis ...
If you burn your hand on a stove you don't keep putting your burnt hand on the same stove again and again while trying to find scientific evidence of why the skin may be melting. Especially after you hear that others got burnt, too.

Color, consistency, smell are properties we all observe while changing oil. RGT was obviously severely degraded much sooner than expected in my engine. That's scientific enough for me. And hearing from others who had the same experience is a confirmation that my observation wasn't an outlier.

Is it possible RGT lasts longer in cooler-running, lower-revving engines? Sure.

If RGT hasn't been discontinued then I stand corrected. Haven't seen it anywhere in a long time.
 
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If you burn your hand on a stove you don't keep putting your burnt hand on the same stove again and again while trying to find scientific evidence of why the skin may be melting. Especially after you hear that others got burnt, too.

Color, consistency, smell are properties we all observe while changing oil. RGT was obviously severely degraded much sooner than expected in my engine. That's scientific enough for me. And hearing from others who had the same experience is a confirmation that my observation wasn't an outlier.

Is it possible RGT lasts longer in cooler-running, lower-revving engines? Sure.

If RGT hasn't been discontinued then I stand corrected. Haven't seen it anywhere in a long time.
I get what you're saying. I just wouldn't put the observations of RGT at the same level as a melting hand or physical pain. I think that's giving them far too much credibility.

As I said, I ran it in my commercial fleet and it wasn't exactly ideal, but there weren't any problems the were identified. The biggest drawback was low TBN and needing to change it out at 7-8K miles instead of 10K. I can buy other oils for the same price (or lower) and get longer life out of them, so that's what I did.

FYI, I don't know if it's been officially discontinued but it is still available at Walmart and other auto parts stores in my area.
 
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has anyone who has had their used RGT analyzed reported results showing the oil has broken down or no longer protects or is "burnt and/or contains a high concentration of undesirable contaminants"...?

I've not seen that and Shell oil has a good reputation...

your car, your choice but I've seen nothing that shows that Shell RGT is any less a "synthetic" than many other choices out there...I'd sure like to see any evidence if there is any...

Bill
I've ran 7 different UOAs on it (5w-20 & 5w-30 in various Ford engines, including 2 EcoBoosts) for between 6K miles and 9K miles and none of the reports indicated any problems compared to previous oils. The numbers were pretty much the same as previous UOAs across the board.
 
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I've ran 7 different UOAs on it (5w-20 & 5w-30 in various Ford engines, including 2 EcoBoosts) for between 6K miles and 9K miles and none of the reports indicated any problems compared to previous oils. The numbers were pretty much the same as previous UOAs across the board.
Which makes sense because emission spectrography isn't for comparative oil quality analysis.
 
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Which makes sense because emission spectrography isn't for comparative oil quality analysis.
So what is? Definitely not smell, sight, touch, taste, or hearing. Do you know of any (legitimate) comparative testing of oil quality we could use for this discussion?
 
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Unhappy customer.. time for another product. Just don't use it no more no need to get scientific about it. You ran it it did what you asked of it.
 
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If you run your vehicle in fairly benign conditions - no extremely low or high environmental temperatures, no high horsepower/rpms, no short tripping, no extended drain intervals, etc., I'm sure I would not expect to see dramatic differences in a single UOA. And maybe I wouldn't see much of any difference at all. Probably the latter.

I don't know the details of your vehicle, driving style, environment, etc. but not seeing big differences in the UOAS might be entirely consistent with what you would expect between a conventional and full synthetic oil in your application.

Where synthetics are going to shine is in those extreme operating conditions or in regular operating conditions over a long period of time. You're just not likely to capture that in a couple of UOAs of some daily driver.
 
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If you burn your hand on a stove you don't keep putting your burnt hand on the same stove again and again while trying to find scientific evidence of why the skin may be melting. Especially after you hear that others got burnt, too.

Color, consistency, smell are properties we all observe while changing oil. RGT was obviously severely degraded much sooner than expected in my engine. That's scientific enough for me. And hearing from others who had the same experience is a confirmation that my observation wasn't an outlier.

Is it possible RGT lasts longer in cooler-running, lower-revving engines? Sure.

If RGT hasn't been discontinued then I stand corrected. Haven't seen it anywhere in a long time.
Except you KNOW whether or not you burned your hand while you have NO idea if the oil is burnt because you can not monitor inside the engine like you can monitor your hand coming into contact with a hot flame. This analogy would be more accurate if you had a piece of wood with a dark mark on it. You assume the dark mark is because it's burnt when in reality someone made the mark with a black sharpie. From 5 feet away and dim light they look identical. You assume WAY too much about the condition of an oil, and unless you're magically omniscient, without scientific instruments and further investigation you have no idea why the oil is dark. This is just basic logic and understanding of the limitation of different forms of evidence - dark oil being about 2 on a scale of 1-10 as far how meaningful that observation is for the basis of a conclusion.
 
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I am running 0w20 RGT in Caravan and change at 200 hours. TFL ran it through the OLM then tested it. Held up fine with all the test they put that HEMI through.
 
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...and here is Shells marketing of their 5W20 RGT.



I bought 50 quarts of 5W20 RGT when Walmart had it on sale for $5.25/5 quarts. I am going to run it in a 2.4L Honda. Won't run it past a 5K OCI. I remember when I bought it the analysis looked almost identical to 5W20 QSUD which I had run before without any issues that I know of.
 
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So what is? Definitely not smell, sight, touch, taste, or hearing. Do you know of any (legitimate) comparative testing of oil quality we could use for this discussion?
None that either you nor me is going to run. Comparative wear testing between oils is a sophisticated, lengthy and expensive standardized test sequence. There's no cheap and dirty way to perform this testing.
 
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None that either you nor me is going to run. Comparative wear testing between oils is a sophisticated, lengthy and expensive standardized test sequence. There's no cheap and dirty way to perform this testing.
You're right. That was my entire point in this whole discussion. If you don't like an oil because of whatever reason, fine. But it just baffles my mind when people who are so quick to dispel "old school" myths (e.g. Pennzoil is full of wax, and you can't switch back to conventional after running synthetic, etc.) using science are so quick to start their own new myths (like RGT burns up after 5K miles). Then when someone tries to say, "Hey, wait a minute, what kind of actual data backs this up?" they are basically dismissed as being too fussy. Instead, people defer back to the human senses as being accurate enough because they don't like admitting their own intuition is very likely wrong. It doesn't make any sense.
 
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Best UOA I've had in my 2018 JL Wrangler 3.6 in terms of wear metals was with a 5k run on RGT 0w20. I prefer Mobil 1, but that UOA killed it. Might be an outlier, though. I ran it one other time and while it did well, it didn't do as well as the most recent run. I've still got about 16 or so quarts in the stash, so it will make its way back into the rotation at some point. I've got Mobil 1 ESP X2 0w20 in it for now. I want to see how that Porsche C20 rating stacks up, Lol!
 
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Best UOA I've had in my 2018 JL Wrangler 3.6 in terms of wear metals was with a 5k run on RGT 0w20. I prefer Mobil 1, but that UOA killed it. Might be an outlier, though. I ran it one other time and while it did well, it didn't do as well as the most recent run. I've still got about 16 or so quarts in the stash, so it will make its way back into the rotation at some point. I've got Mobil 1 ESP X2 0w20 in it for now. I want to see how that Porsche C20 rating stacks up, Lol!
What are you looking at on the UOA to make a qualitative determination between two oils?
 
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What are you looking at on the UOA to make a qualitative determination between two oils?
Wear metals, mainly iron, were at all time lows for this engine, even adjusting for miles. Flash point was also a little better than typical. I've done enough UOA's in this engine to see the trends and know what is typical. It was the best UOA yet, overall. If the next one with the X2 shows similar results, then I'll chalk it up to the engine at this point in its life. If it gets back to what is typical, then I'll give the RGT the credit until another RGT UOA shows it to be an anomoly.
 
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I've not heard, seen or smelled any difference in the Shell RGT I've used in 5W-30 in a Ford F-150 with an ailing 5.4 or a Cadillac CTS with the 3.0 DI over several oil changes...

I only bought the Shell RGT when on closeout and I couldn't source Mobil 1 with the rebate a couple years back but I've not seen any evidence that the Shell RGT is a poor choice in a synthetic oil beyond a recommendation to use a lower calcium oil (mobil 1 was recommended as was A/C Delco full synthetic natch ;) )in a Chevrolet Malibu with the 2.0 Turbo...

Bill
 
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