Group III vs Group IV (PAO) Basestocks in the TDI Engine

TooSlick · December 13th, 2002, 15:48

Suggested Reading:

SAE Paper # 2002-01-2678

"Formulation Effects in a Severe Passenger Car Diesel Engine Test"

This paper compares the performance of Group III and PAO based synthetic oils in the TDI engine, specifically with regards to piston deposits and ring sticking. It also addresses the issue of variability in Group III basestocks and their performance in the VW "T-4" engine test, which is part of the VW 502 specification.

A very interesting read that clarifies why most if not all of the VW 506 oils in Europe are 0w-30, PAO based products.

TS

Natureboy · December 13th, 2002, 16:10

Quote:

Originally posted by TooSlick:
Suggested Reading:

SAE Paper # 2002-01-2678

"Formulation Effects in a Severe Passenger Car Diesel Engine Test"

This paper compares the performance of Group III and PAO based synthetic oils in the TDI engine, specifically with regards to piston deposits and ring sticking. It also addresses the issue of variability in Group III basestocks and their performance in the VW "T-4" engine test, which is part of the VW 502 specification.

A very interesting read that clarifies why most if not all of the VW 506 oils in Europe are 0w-30, PAO based products.

TS

<font size="2" face="Verdana, Helvetica, sans-serif">TS,
How do I get ahold of this? Am I good at flaunting my ignorance or what?

NB

dieseldorf · December 13th, 2002, 16:33

Ted, why not demonstrate a little xmas gererosity and share with us the key points??...as you see them, of course!

HO HO HO.

December 13th, 2002, 17:07

heh heh heh, I sent TwoSlick the SAE link for the paper. Looks like SynLube PAO is the ONLY way to go with a TDI after all, BAR NONE [img]images/icons/shocked.gif[/img] ...... [img]images/icons/grin.gif[/img]

spoilsport · December 13th, 2002, 17:20

How can we get our hands on this SynLube ?

sootandclatter · December 13th, 2002, 18:08

Try Amsoil lol, has all the goodies!!! [img]images/icons/grin.gif[/img] [img]images/icons/grin.gif[/img]

Georgeseq · December 13th, 2002, 18:34

Synlube is also spelled Delvac 1. It is also called "real" synthetic vs. Group III wannabees.. I am anxious to hear GeWilli's comments on the report....
George

Clueless One · December 14th, 2002, 04:12

The link for the paper is:

http://www.sae.org/servlets/productD...D=2002-01-2678

enjoy!

SoTxBill · December 14th, 2002, 07:01

how bout posting the one where the ran a fleet of cabs with the same additives,,, but only chagned the base.. they ran pao vrs group III...

the purpose of the test was to show the difference between the two bases,, with the additives being exactly the same...

there are several tests like that that have been run.. and these type test dont sell oil,, they are to scientifically develop to gather true performance of the oils so that changes can be made...... not to show in a specialized test that my dog is bigger that yours.. hell i've got a toaster that does 0 to 60 in 6 seconds...

why do you pick only the tests you want??

GeWilli · December 14th, 2002, 08:32

I've got it printed out and will digest it . . . and comment in a bit [img]images/icons/wink.gif[/img]

First Comment is So what? Whats the big deal? This paper says kinda what we know already . . .

The bone I have with this is that it doesn't identify more chemically the differences between the variablity and what leads to the failures.

Looking at their 4 test oils, the Group IV 0W-30, the Group III/IV 5W-30, and the Group IV 0W-40 and the Group III/IV 5W-40 I think it becomes hard to determine anything more than a comparison to those very specific formulations.

The low polymer oils (lower visc modifier meaning the 0W-30 and 5W-30 oils) did much better. And that is as expected. The additive choices clearly are just as important as base stock.

The one thing that is clear is there were 2 Group III 5W-30 oils that peformed perfectly in the tests (these are off the shelf not blended for the tests like the ohter oils).

So what can we get out of it?

Well not much IMO.

The Petro Canada 0W-30 oil I am using is a Group III/IV blend, and the wear metals are very similar to the results I've gotten with a Group IV/V blend 0W-30 so I would feel reasonably comfortable saying that the oil is doing its job.

I've run a compression check a while ago and it was over 500 PSI across the board - no loss of compression - nearly as high as some xW-40 oils tested. That was between 80 and 90,000 miles on the ODO. so quite a few hours running the Group III/IV blend.

Yes Group III quality is variable. Hence my desire to avoid group III oils coming from anywhere other than Petro Canada's refineries. And my reluctance to reccomend Rotella T 5W-40 synthetic.

My other question I have from reading this paper is what does adding a Group V oil to the PAO do to the results? I know of only a very few PAO only oils on the market and they are there only (my guess) for limited (very) markets and are very low production batch oils.

What does this mean for the TDI? Well they ran a bunch of tests - and killed a boat load of TDI engines to write a short 7 page paper [img]images/icons/wink.gif[/img] with little meaning for the North American market [img]images/icons/tongue.gif[/img]

But it does questions quite significantly the intelligence of running a high polymer treat oil (PAO or Group III). 5W-40 doesn't look like a very good viscosity. So I might join Tbill in saying if you are down somewhere warm and can't grasp that a 0 or 5W-30 is perfectly acceptable irregardless of ambient temps (to run in the TDI) then run a 15W-40, not a 5W-40.

I'd also wager that 300,000 miles in Delvac-1 vs a sister engine run 300,000 miles with Amsoil Series 3000, will demonstrate significantly higher piston ring deposits and much MUCH lower merit scores. I would also feel confident that anyone running the Amsoil 10W-40 will see increased piston ring deposits over either the Series 3000, or Series 2000 0W-30 or even the 15W-40 HD oil.

As it was written here many moons ago by someone who had more to give and less to snipe about (at that time) 0W-30 is ideal for the Garret Turbo and with this evidence a 0w-30 or 5W-30 properly formulated oil is better for the rest of the engine.

(all opinions expressed in this post are mine, I have no connection to any monetary rewards from sales of oil or oil related products. These are opions, some based on more than others but that is it. take is for what it is and deal with it [img]images/icons/wink.gif[/img] [img]images/icons/tongue.gif[/img] )

[ December 14, 2002, 09:20: Message edited by: GeWilli ]

GeWilli · December 14th, 2002, 09:23

Quote:

Originally posted by SoTxBill:
how bout posting the one where the ran a fleet of cabs with the same additives,,, but only chagned the base.. they ran pao vrs group III...

<font size="2" face="Verdana, Helvetica, sans-serif">If that is the report I've read they found that the ideal oil for reduced wear and highest fuel economy was a group III/IV blend! the group III/IV blend beat out even the pure IV oil!

smokin' · December 15th, 2002, 00:35

A friend of mine works for a national mechanical operations/repair chain. He said that they have recently switched from pure synthetic lubes to mixed synthetic-blends for most applications. He said that in-house testing, and field results, supported that the blends were providing the best of both worlds. I guess there are some things that petroleum can do better than a poly. Of course for the extremes, synth is the way to go. [img]images/icons/grin.gif[/img] [img]images/icons/cool.gif[/img]

smokin' · December 15th, 2002, 00:42

BTW, who makes a decent Group III/IV blend?

TEXAS_TDI · December 15th, 2002, 00:49

Quote:

Originally posted by smokin':
BTW, who makes a decent Group III/IV blend?

Semi-Synthetic 10W-40 Motor Oil

Synthetic Blend 15W-40 Diesel Oil

[ December 14, 2002, 12:50: Message edited by: ProjektZwoTDI ]

eidie2 · December 15th, 2002, 15:51

I'm not used to reading SAE papers, so I have a few questions.

What are they saying in the piston cleanliness section? That the 40W oils could not do the test, the test is flawed, the oil failed, why did they "abort the test" on the 40Ws? They are clearly higher early on, but he PAO 40W is dropping fast, but they cut it off at 36 hrs too.

Next question
Why do they not call out the names of the dispersents X,Y, and Z. Does anyone have a good enough grasp of the properties of dispersents to see if they are saying what Z is, and since it appears they recommend against a heavy usuage of it in our oil.

About the same test. Why did they only perform this with group 3 oils, why not group 4.

I am just a little lost by it. I gathered from the artile that lighter PAO oils have a better affect on piston cleanliness, and are significantly better than the industry standard oil 15W-40 and even better than 0W-40 PAOs. Did I miss something?

[ December 15, 2002, 15:52: Message edited by: eidie2 ]