Shell Rotella Gas Truck 5W-30 vs. Shell Rotella T6 Multi-Vehicle 5W-30 compared

[OVERKILL]

Originally Posted by SubieRubyRoo
Originally Posted by Mad_Hatter
Isn't it as VI goes up the volatility goes down?


I don't think it's entirely scientific (VI vs. volatility), but I have generally seen the opposite. An oil like Eneos Sustina 0W20 with a VI of 227 had a Noack of around 13%, while the Amsoil SS 10W30 with a VI of 147 has a Noack of about 4.7%. Others generally seem to follow this trend, even in one manufacturer's line of oils such as Amsoil SS.


Yup, that's been my observation as well. Use of higher visc, higher quality base oils with less VII will result in a lower NOACK, whilst the use of a lighter, less expensive base with more VII will result in a higher volatility. See Ravenol SSL 0w-40 @ 8% (PAO) versus SOPUS SRT 0w-40 at >13%.

 

[Mad_Hatter]

Originally Posted by SubieRubyRoo
Originally Posted by Mad_Hatter
Isn't it as VI goes up the volatility goes down?


I don't think it's entirely scientific (VI vs. volatility), but I have generally seen the opposite. An oil like Eneos Sustina 0W20 with a VI of 227 had a Noack of around 13%, while the Amsoil SS 10W30 with a VI of 147 has a Noack of about 4.7%. Others generally seem to follow this trend, even in one manufacturer's line of oils such as Amsoil SS.

I believe you're right. I was working off memory and I got it wrong. I believe it is for minerals, as base oil viscosity goes down, volatility tends to increase. So viscosity down, volatility up and not VI up, volatility down as I previously stated - sorry for the confusion.

PAO's have better volatility than minerals at low viscosity.

 

[Mad_Hatter]

Originally Posted by ARCOgraphite
Originally Posted by Gokhan
Shell Rotella Gas Truck 5W-30 has becoming popular lately because SUVs and pickup trucks are popular, and this oil claims to be tailored for them. However, is it for real or a marketing hype? ....

Moral of the story: Don't go with the marketing hype -- go with the certifications. .....

Disclaimer: The calculations/estimates are only based on the viscosity data. There is no way to estimate the quality of the additive pack without engine and bench tests, other than from the certifications/OEM approvals claimed.


_______

A Thicker oil wont reduce wear if the film provided by the thinner oil is adequate.
_______

I am going to challenge the logic a bit here as the argument demands the challenge.

The extension of this logic is that an HD SAE30 with a C service category is "best" , and
anything else is a compromise bowing to spark ignition engines, fuel economy reqs
and to multi-viscosity, cold climate demands.

If this is found disagreeable, We are back to the assertion above this first argument
________

RGT is an ILSAC GF-5 Oil and bound by GF-5.

This is an Apples to Oranges comparison

RGT is not a CK category oil

So marketing - maybe a bit, but We still don't know.

Is RGT a bit more viscous and does it have a bit more AW adds?'

Is that enough to that validate the marketing for most consumers?

Now the valid comparison should really be between QSUD (or PP) or M1 and RGT

So, go at it again GOHKAN and let us come to a more valid assumption.

But thanks for the work so far. It is thought provoking.

-Ken


Good points. Question, RGT is D1G2..do Dexos requirements place limits, like fuel efficiency, on RGT that T6 MV doesn't have being CK4? Plus, T6 MV isn't SN+ but it does carry other approvals to which I'm not an "expert" on... but would you "risk" running the T6 MV in a tgdi engine? I'm not sure this is a totally apples to apples thing... and at the end of the day, how many of us are realistically going to push our gas cars/trucks to the limits of RGT's (cap)abilities??? I'll be the first one to say, I won't. My driving is mostly the mundane in town type with the occasional highway trip. So for me, while this comparison is interesting... it's purely academic. (which is what, 90% of what we do here?...‚)

 

[Gokhan]

Originally Posted by ofelas
What would the base oil viscosities of these two 5w30s be ?

1/ https://www.amsoil.com/lit/databulletins/g2880.pdf

2/ https://www.amsoil.com/lit/databulletins/g1301.pdf

Thx

Base-oil viscosity at 150 C:

Amsoil Signature Series ASL 5W-30: 2.3 cP
Amsoil Series 3000 HDD 5W-30: 2.7 cP

 

[Gokhan]

Originally Posted by OS4A
Gokhan

Timely thread I can contribute to.

Here is a link to a recent UOA on T6 5w-30 MV off a 2019 Subaru FB20 engine for one data point.

https://www.bobistheoilguy.com/foru...t-rotella-5w-30-mv-5820-mile#Post5329420

I tend to use the same oil/filter a minimum of three times for data consistency so there will be at least one more UOA on this engine in about 6 months running T6 5w-30 MV.

Whew, you switched from an ILSAC 0W-20 (HTHS = 2.6 cP) to a thick HDEO (HTHS = 3.5 cP)?

It's good to see the wear numbers went down, but at this point we don't know if you're still observing engine-break-in effects. It would be very interesting if you could do some 0W-20 UOAs in the future for a better comparison, with the engine-break-in effects having subsided.

In order to answer others, it's probably an overkill to switch from an ILSAC 5W-30 (HTHS ~ 3.0 cP) to a thick 5W-30 (HTHS = 3.5 cP) for normal driving conditions. However, a thicker oil would definitely help if the vehicle is driven hard, as every Toyota manual mentions for example.

As for the Rotella Gas Truck 5W-30, this particular oil doesn't really seem to be suited for demanding truck engines because of its high VII content, which promotes engine and turbocharger deposits and may increase engine wear. High VII content is good for fuel economy though. If I was looking for a "stout"

dexos1 Gen 2 5W-30, I would stay away from it and pick up the regular Pennzoil Platinum 5W-30 (base-oil viscosity at 150 C ~ 2.3 cP). Valvoline Advanced Synthetic 5W-30 has an unusually thick base oil (~ 2.8 cP at 150 C), unusually low relative VII content (~ 2%), and unusually high HTHS (3.2 cP) if you're looking for an ILSAC 5W-30 that is pushing into the thick-oil territory. Can we use the word stout synonymously with thick on BITOG -- stout base oil, stout HTHS, etc.?

PS: Blenders in Shell seem to have chosen to raise the KV100 of Rotella Gas Truck 5W-30 over of a typical 5W-30 (such as Pennzoil Platinum 5W-30) by using about twice the VII they normally use and on a thinner base oil. This is a very strange thing to do, as a higher KV100 doesn't help with anything except for oil leaks and oil consumption through valve-stem oil seals. For a healthy engine, I would prefer low VII content and low KV100 for a given desired HTHS, as this results in best performance for engine and turbocharger deposits and engine wear, as it (1) results in a thicker base oil and (2) avoids the deposit-forming tendencies of the VII.

 

[CT8]

Wold there be a benefit running the "greater" oil over the lesser oil if the engine recommended the lesser oil?

 

[Mad_Hatter]

Originally Posted by CT8
Wold there be a benefit running the "greater" oil over the lesser oil if the engine recommended the lesser oil?

Not exactly sure what you mean by greater and lesser but if you are referring to thickness at 150c (HTHS) than I would think so long as the oil you're using maintains a sufficiently thick wedge of oil (oil film thickness) between the moving parts, thicker wouldn't necessarily improve wear rates. I think this is what Arco' was getting at. In fact using 'too thick' of an oil could promote power loss and friction. Anyhow, maybe Gokhan can expand on this or correct it if I'm wrong.

 

[OilUzer]

Originally Posted by Snagglefoot
It appears no one mentioned moly. RGT has 160 ppm moly. Rotella MV has 3 ppm as per a VOA that was posted. Doesn't matter much to me but maybe the moly fans might care.

you don't have to worry about others ... admit it. You like moly

If they add that moly to T6 MV, I may consider it

 

[Triple_Se7en]

Originally Posted by OilUzer
Originally Posted by Snagglefoot
It appears no one mentioned moly. RGT has 160 ppm moly. Rotella MV has 3 ppm as per a VOA that was posted. Doesn't matter much to me but maybe the moly fans might care.

you don't have to worry about others ... admit it. You like moly

If they add that moly to T6 MV, I may consider it

Titanium or Tungsten over Moly in a first round KO.

 

[kschachn]

Originally Posted by Triple_Se7en
Titanium or Tungsten over Moly in a first round KO.

I've always wondered how titanium or tungsten was better, those are just the central ions in an organometallic compound, right? How do they deliver a knockout punch over the molybdenum compound?

 

[Triple_Se7en]

kschachn
I'm not spending hours copying & pasting research for you. If you want to know, then seek Google.com's blank white search box yourself.

 

[kschachn]

Originally Posted by Triple_Se7en
I'm not spending hours copying & pasting research for you. If you want to know, then seek Google.com's blank white search box yourself.

I really don't know and was interested in finding out the details. The way you made your post it sounded like you knew, sorry I guess not.

 

[Triple_Se7en]

Today I researched Ravenol DXG SAE 5W30. Copy and paste it in Google. That's a good start.
See what Google says about SP / GF-6 oil additives coming. Large doses of Moly aren't in the loop with it.
Move along now kschachn...... do your own homework.

 

[kschachn]

Originally Posted by Triple_Se7en
Today I researched Ravenol DXG SAE 5W30. Copy and paste it in Google. That's a good start.

Looks like it uses a molybdenum compound too, along with a tungsten one. I didn't see much there about the ligand chemistry, but thanks anyway.

 

[Triple_Se7en]

Originally Posted by kschachn
Originally Posted by Triple_Se7en
Today I researched Ravenol DXG SAE 5W30. Copy and paste it in Google. That's a good start.

Looks like it uses a molybdenum compound too, along with a tungsten one. I didn't see much there about the ligand chemistry, but thanks anyway.

That's because Moly and Titanium are known to clash. A little Tungsten and a little Moly doesn't.
You're starting to get warmer. Keep reading. I'm outa' this thread. I need more Google research on T6 MV and ESP. Good luck!

 

[kschachn]

Okay, that's probably best.

 

[Gokhan]

Originally Posted by Mad_Hatter
Originally Posted by CT8
Wold there be a benefit running the "greater" oil over the lesser oil if the engine recommended the lesser oil?

Not exactly sure what you mean by greater and lesser but if you are referring to thickness at 150c (HTHS) than I would think so long as the oil you're using maintains a sufficiently thick wedge of oil (oil film thickness) between the moving parts, thicker wouldn't necessarily improve wear rates. I think this is what Arco' was getting at. In fact using 'too thick' of an oil could promote power loss and friction. Anyhow, maybe Gokhan can expand on this or correct it if I'm wrong.

You need to look at both the HTHS viscosity and base-oil viscosity. HTHS viscosity is measured at a shear rate of 1,000,000 per second, which can be easily exceeded by a factor of 10 or more in demanding driving conditions, such as wide-open throttle. When that happens your actual dynamic viscosity will be less than the HTHS viscosity and closer to the base-oil viscosity. Moreover, in certain parts of the engine, such as the valvetrain and timing chain, shear rates are extreme regardless of the driving conditions, and the base-oil viscosity is the relevant viscosity, not the HTHS viscosity.

Since the base-oil viscosity is not reported and it's unlikely that you will use my calculator, the best way of estimating it is to look at KV100. For a given HTHS, an oil with a lower KV100 will have a higher base-oil viscosity and oil with a higher KV100 will have a lower base-oil viscosity. An oil with a higher KV100 will usually have a higher viscosity index (VI) as well. That's because, for a given HTHS, an oil with a higher KV100 has more viscosity-index improver (VII).

• Therefore, if you care about wear and deposit control but not fuel economy, for a given HTHS viscosity, choose an oil with the lowest KV100 and lowest VI. This oil will have the least amount of VII and will run the thickest in most dynamic (shear) conditions. (Moreover, lower VI implies thicker oil in normal oil temperatures, which are usually lower than 150 C at which HTHS is reported.)
• Alternatively, if you care about fuel economy but not wear and deposit control, for a given HTHS viscosity, choose an oil with the highest KV100 and highest VI. This oil will have the most amount of VII and will run the thinnest in most dynamic (shear) conditions. (Moreover, higher VI implies thinner oil in normal oil temperatures, which are usually lower than 150 C at which HTHS is reported.)

The HTHS viscosity was invented to have a more relevant viscosity for engine protection and performance, but researchers have lately discovered that the HTHS viscosity alone is insufficient to predict viscosity-related engine protection and performance and the base-oil viscosity also matters. If you want to have a more meaningful prediction of wear and fuel economy, you need to take into account both. To learn technical details about it, see this thread:

VII (VM), shear, base-oil viscosity, HTHSV, friction, and wear: State of the art

 

[SR5]

For those tough gas truck drivers, the stout oil to get is

Shell Helix Ultra 5W-30 also called Pennzoil Platinum Euro 5W30 in North America.
It's a GTL (PurePlus) based full synthetic oil.
It's rated API SN-Plus, ACEA A3/B4, BMW LL-01, MB 229.5 / 226.5 and Renault RN 0700 / 0710.

From the specs alone, we know it's a 5W30 that has passed LSPI tests for TDGI engines (SN-Plus), has a Noack of 10% or lower (MB 229.5), a TBN of 10 or more for long life ( A3/B4), a HTHS of 3.5 cP or more for extra wear protection (A3/B4) plus lots more BMW and MB test for low wear and deposit control. It would be required to pass a stay-in-grade shear stability test.

Dexos is good and all that, but you only need a Noack of 13% to pass Dexos (15% for API), and neither include a shear stability test like ACEA or the wear and deposit tests of the Euro OEMs.

Sure, no strong fuel economy requirements, but you can't have everything. And most of us would never notice the difference. (And never start a sentence with "and" !)

https://shell-livedocs.com/data/published/en/dcb9ca69-19d5-452c-be13-aabb117dc6d7.pdf

 

[RDY4WAR]

As a note, Shell's star polymers are also pretty rock solid when it comes to shear stability. I wouldn't worry about RTG holding its grade.

 

[stanlee]

RGT is a Dexos spec'd oil, T6 is a diesel oil suitable for gasoline so...yeah are we to be shocked.