I recall a while back there was some discussion about whether to go synthetic or not and what brand one should use. Recently, a couple people on vwvortex.com had both mobil 1 0w-40 and amsoil 5w-30 analyzed. The results were that the Mobil 1 held up pretty well at a 5000 mile drain interval. The amsoil, on the other hand, was beginning to go at 5200 miles. Interesting that amsoil advertises long drain intervals as one of its cost justifications but it seemed to be breaking down at 5200 miles in a stock Volkswagen 1.8t engine. The guy who analyzed the mobil 1 was running a "chipped" (modified for more performance) and drove harder than the guy with the amsoil. Yet, even in the modified engine, the Mobil 1 held up better.

So my Amsoil gets analyzed at 10,000 mile change intervals:

OXD 7.8%
NOX 27.1%
TBN 11.4

All wear metals (where are his numbers?) very low.

Car has 230,000 miles and is a turbo driven pretty hard. One data point? Big deal. How do we know the guys car is well tuned, etc?

I never saw anything much on the site (it is huge!) - mostly hot air :)...OK most are water cooled. (sorry)
--
http://www.fidalgo.net/~brook4/oilslubesfilters.html

Here is his post, which includes his numbers. If you have a problem with it, don't flame me, go and respond to him. His name is Daisycutter and he roams the vwvortex.com 1.8T forum.

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Thread: Amsoil 5w-30 (not XL) analyzed. 4:06pm 8-13-2002

An fyi (please no oil flame wars) only to those interested...
I had an oil analysis run on my Passat with 1.8T with no mods other than ITG air filter. Analysis was done on 5200 miles during a hot humid summer here in New England with lots of AC use. Car averages 70-90mph (although I did push it more given I wanted a worse case scenerio for this particular vehicle). The car does see a moderate amount of traffic (idling).

Everything else looked good, but here's the important part of the analysis:

TBN 7 starts at 12 so your engine is
depleting this, like nitration needs to be monitored.

Vis 12.6 thickened to 40w barely,limit
is 12.5 for 30 w. Amsoil is not holding up, I can't see extended drains
with this oil.

It looks like I'll be doing 5,000 mile drains to error on the side of caution.


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Everything else looked good, but here's the important part of the analysis:

>>>>TBN 7 starts at 12 so your engine is
depleting this, like nitration needs to be monitored.

If there is an engine problem, such as EGR, which causes increase in nitration, the TBN will drop and the oil will thicken

>>>>Vis 12.6 thickened to 40w barely,limit
is 12.5 for 30 w. Amsoil is not holding up, I can't see extended drains
with this oil.

Sure looks like there is a mechanical problem, although maybe not super severe.
As I understand it, an oil can go out of grade by one step and still be usuable. The difference between 12.5 and 12.6 is pretty minor, though it is a grade on the scale.


Would be interesting to see what Mobil 1 would do in this same engine under the same circumstances.

Sorry - wasn't flaming you - I thank you for taking the time to post this here. I just want to keep facts on the table.

I'll assume for a minute the analytical numbers are correct. Let chat about the two of over 20-25 numbers you typically get on an analysis sheet.

TBN=Total Base Number - this is chemically (on an acid-base scale) an amount of base added to a new motor oil to nuetralize any acids. Acids that come from blow by, condensation in the oil, contamination, etc. Notice the words in his post "your engine is depleting this". This tells me something about his engine - there may be something wrong and the oil is doing it's job. The oil is not crapping out. His conclusion is incorrect. For what it's worth Amsoil 5W-30 starts at 11 TBN, not 12. (Most petroleum oils start at about TBN 6 or so)

Viscosity is at 100°C. His oil started new at 11.7 cSt. An increase of 0.9 cSt to 12.6 is not alarming. The oil is a 5W-30 and yes the upper limit on NEW straight SAE 30W is 12.5 cSt.

By his own admission (and ommision): "Everything else looked good..." this means wear metals (critical!!), oxidation (a real measure of how the oil is holding up!) What was the lab's conclusion?

The statement that the Amsoil "not holding up" makes me call BS, that's all.
--
http://www.fidalgo.net/~brook4/oilslubesfilters.html

Thanks for setting the facts straight. I'm interested in finding the best oil for both my Volvo and VW and would like to learn as much as possible about good oils. Our goal is to drive each of our two turbo vehicles well beyond 100k miles, hopefully on the original turbo. By the way, are you familiar with the forum by bobtheoilguy? I just happened on it last night and found the same thread posted there. Here's the link:

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000098

In that VW 1.8 Turbo, is the turbo water cooled???
--
www.fidalgo.net/~brook4

Bob seems OK, but I haven't studied him in depth......

Another thing I forgot to mention. Several of the posts say that the Amsoil 5W-30 is a 25,000 mile motor oil. Well maybe in a NA car, but in a Turbo - even optimistic Amsoil corporate says: 10,000 miles max!! That should really tell us something about just how hard turbochargers are on oil. So we chip our cars, crank the boost way up, mix high rev boosts with city idling....yikes!



--
www.fidalgo.net/~brook4

Those numbers seem fine for a turbo charged engine. My S70 T5 on Amsoil 10W-30 has the following numbers in a 5K mile change.

NOX = 37.1
OXD = 15.6
Viscosity = 11.7
TBN = 8.3

With these numbers, I could easily extend the intervals to 10K. Next change will be a 7500 mile change. I'll analyze again and see where I'm at.

It's important to remember that all of these numbers are dependent on many variables. One thing that we all have in favor over many other vehicles is the size of our crankcase; it’s very large (6 quarts) relative to a small displacement (2.0-2.5). For example, a small block GM V8 typically has a 5 quart crankcase (5.0-5.7 L engines). For a given engine displacement, the more oil you have circulating around the engine, the longer the oil is going to last.

Does anybody know what the crankcase capacity is on a VW 1.8T?
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1999 S70 T5

There are two VW 1.8T's. The one in the Passat is the Audi 1.8T which has 170 horsepowers and a capacity of 4.2 quarts. The other 1.8t (found in Jettas, GTI's and the other VW's) has 180 hp and a capacity of 4.6. The guy that had Amsoil analyzed has the Passat 1.8 (4.2 quarts). The guy that had the Mobil analyzed has a Jetta (4.6 quarts). That could explain why the Mobil 1 performed better. But also keep in mind that the Passat 1.8T is a lower output engine (170 hp instead of 180). Moreover, the guy running the Mobil 1 also has a modified engine so he boosted up from 180 hp to 225 hp or so. I would assume that the more demanding engine would be harder on the oil. Is it enough to offset the .4 difference is oil capacity? I'm not sure.

I use whatever the dealer puts in.

That said, there are way too many variables to compare the oil quality of just two cars.

The car driven harder could take longer trips and come up to proper operating temperature, while the other does not.

I'm sure that you will get some responses to this post!
--
2 8s & 2 7s 600,000 miles total

volvoandvw,

Can you give us a more specific URL than simply vwvortex.com.

I'd like to read the full story on what you are relating, but the vwvortex.com site is quite extensive and I'd spend all day there trying to find what you are talking about.

Thanks.

One more thing, Daisycutter also posted on a oil discussion in the Passat b5 forum in vwvortex. The title is "5w-30 or 5w-40 oil discussion". His summary of his analysis was:


The results were fine, except that this oil needed to be changed at 5,000. I wouldn't push it past 5,000 in the future based on the results. If Amsoil 5W-30 was on the way out at 5,000 (bear in mind that this is a 25,000 mile oil) then I wonder what some of the 5W-30 dino oils would look like under similar conditions? Perhaps fine, but I'm not gonna find out for myself. I think I'm gonna try lubro-moly at the 25,000 mile change and get that tested. It's only $5 a quart and if it looks good at 5,000 I'll stick with that, nothing against Amsoil. I'm gonna stick to the 5,000 mile interval for now regardless of the extra expense of synthetic and go with 5W-40 for future changes. If lubro-moly is holding up well at 5,000 I'll check it again at 7,500.

Ken,

Go to www.vwvortex.com and go the "forums"
Then go the the "1.8T Forum" and look for the thread titled:
"Amsoil 5w-30 (not XL) analyzed".

The thread is buried a few pages back so you will have to dig a bit. As of right now, 5:30 East Coast time, it is on page 4 of the 1.8T forum messages. The author is "DaisyCutter".

There was also a thread a few weeks ago started by dbrowne1 that analyzed Mobil 1 5w-30 (sorry I said 0w-40 at first). This might be buried pretty far back by now so you will really have to dig. But in a nutshell, dbrowne said the Mobil 1 held up well.