Amsoil 0w-40/"AFF", 10k miles in 2002, Audi TT

[TooSlick]

I have a pretty good idea what's happening here in terms of "viscometric" behavior, but I'd be interested in what other folks have to say.

I should note that this formulation doesn't carry the VW 502.00/505.00 specs, or even ACEA A3/B4, and Amsoil doesn't recommend it for this application. It does show that high quality, PAO/Ester synthetics tend to be pretty versatile....

2002 Audi TT Quattro Roadster, 1.8L/225 Hp
Amsoil 0w-40, "Four Stroke" oil
Miles on engine, 60,000
Miles on oil, 10,000
Oil consumption, 0.75 qts
OEM air/oil filters

Physical/Chemical properties:

water/glycol, none
fuel < 0.5%
oxidation, 28 abs/cm
nitration, 36 abs/cm
*Viscosity @ 100C, 15.8 Cst*
TBN, ASTM D-4739, 4.25

Wear Metals:

Fe, 10 ppm
Cr, 0 ppm
Pb, 0 ppm
Cu, 12 ppm
Sn, 0 ppm
Al, 1 ppm
Ni, 0 ppm
Na, 0 ppm
K, 0 ppm

Silicon, 14 ppm


Oil Additives:

Boron,38 ppm
Mg, 816 ppm
Ca, 2769 ppm
Phos, 1115 ppm
Zn, 1312 ppm

TS

 

[buster]

This oil clearly isn't API SM/SL approved. I've seen UOA's with this engine before. Like Toyota engines, it shows very low wear. Good engine.

The viscosity probbly thickend back up now that you are at 10k miles. Or being they aren't concerned about meeting any fuel efficiency tests, it contains more esters like Redline, making it more shear stable.

Ted, as a comparison you should run M1 0w-40 next but compare your MPG numbers.

 

[TooSlick]

Buster,

I was honestly surprised by these results, as I did expect this oil to shear in the turbo. In retrospect I think this oil has a basestock blend similar to the Amsoil 0w-30. That is, there is some lightweight component to the basestock blend that evaporates over time and causes the oil to thicken slightly. The solids level is also pretty high at this point. I thought about running it again and testing it after 3000 miles,but I don't think it sheared much at all.

Fuel efficiency with this oil was about 27.0-27.5 mpg and it stayed that way for the entire service interval. This oil IS an SL/CF formulation - the xw-40's don't have to meet any chemical limits for phosphorus.

I have several more Amsoil formulations to test yet, so I'll pass on the M1 0w-40 for now.

TS

 

[SSDude]

Too Slick,

This appears to be outstanding oil with a high level of detergency. What was the startng viscosity for this oil. Do you think it sheared and then oxidized? As you stated, it did not shear like most 0w-40s. I

 

[TooSlick]

Baseline TBN is approx 11.0 and baseline viscosity for the current formulation is listed @ 14.4 Cst.

I think it may have sheared by perhaps 5%-10% and it has thickened due to oxidation and nitration in the last few thousand miles. This oil really isn't intended as an extended drain oil for turbos - but I like to overtest things.

It's an all climate oil for PWC's and four stroke snowmobiles. You could also use it for Motorcycles in cold weather. It meets the latest JASO MA2 specification for wet clutch use.

Wear rates are about what I've seen with the other three Amsoil formulations and the TBN is about one point lower. The TBN's of the other Amsoil formulations are running in the 5.0-5.5 range after 10,000 miles in this TT.

TS

 

[buster]

quote:

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Oxidation is quite high, thus it may've been the sole cause of the viscosity bump. Perhaps this oil has lesser oxidation control in comparison to M1, 0w-40?

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Very possible. I think in general, Amsoil does not do as good of a job as M1 in terms of oxidation. Probably bc XOM saves the best PAO's for M1.

 

[Pablo]

This oil is not necessarily designed for long drain intervals. Taking lab error and true starting vis. (vs. typical properties) into account the oil didn't thicken all that much. Wear numbers are good. TBN healthy.

I never put much into a stand alone oxidation number. Show me the virgin oxidation number.

 

[SSDude]

Whether the oil oxidized or not is irrelevant. This is a very good looking UOA. I just asked because I am curious. I like to experiment like TooSlick. I am currently debating runnnig John Deere 0w-40 or M1 5w-40 next in my car. Once again thanks TooSlick for this interesting experiment.

 

[TooSlick]

Most of the folks I've seen are running 5k intervals in this 1.8L turbo engine. These are outstanding wear numbers for a 10k interval, in fact you'd be hard pressed to improve upon them. I expect the S2000 and S3000 to hold up better over 10k, but I doubt the wear rates are any better than this.

TS

 

[buster]

quote:

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It's an all climate oil for PWC's and four stroke snowmobiles. You could also use it for Motorcycles in cold weather. It meets the latest JASO MA2 specification for wet clutch use.

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I'm sure an oil like this has it's place, as you stated, but I wouldn't run it in a modern four stroke engine with that much ZDDP. However, in some engines, I don't think it would be a problem.

This oil is built more like a race oil with the add pack the way it is. It's very hard to tell whether it sheared or thickend back up being the drain interval is 10k miles. I do believe you can make a shear stable 0w-40 - ex. - Esso 0w-40, RL 0w-40 etc. Of course that is of no interest these days with fuel efficiency being the big push.

 

[The Critic]

Oxidation is quite high, thus it may've been the sole cause of the viscosity bump. Perhaps this oil has lesser oxidation control in comparison to M1, 0w-40?

What oil are you running now?

 

[Brons2]

i agree, nice wear numbers! very nice!

who's worried about a little viscosity bump?

 

[Patman]

Very impressive indeed! I would've expected this oil to shear like crazy, and I wouldn't have expected the TBN to be so good after 10k either! I wonder why Amsoil doesn't market this oil for cars? I'm sure they could!

 

[buster]

quote:

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I wonder why Amsoil doesn't market this oil for cars?

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If they made it for cars, it would become less shear stable and have much less ZDDP to meet the SM spec. On top of that, they would have to make it less shear stable to meet fuel efficiency specs. No brainer.

This engine shows low wear on any oil so I'm not really impressed by the wear numbers.

quote:

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AMSOIL Formula 4-Stroke® Power Sports Synthetic Motor Oil (AFF) is specially formulated for four-stroke recreational motors, ATVs and snowmobiles. Reduces wear. Wet clutch compatible. Contains no friction modifiers. Broad viscosity range makes it excellent for use in both hot and cold weather conditions.

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Ted, how are you seeing no decrease in MPG with an oil that has no FM's?

 

[TooSlick]

Patman,

I'm sure they could market this oil for cars, but SAE 0w-40 is a non-standard grade for 95% of the vehicles out there. Amsoil already has their 5w-40 Euro oil and they are promoting their 10w-40 for high mileage vehicles and those that see severe service conditions. So there simply wouldn't be much of a market for a 0w-40 SM rated formulation.
The main reason the Mobil 1, 0w-40 exists is the European market, where this grade is still popular. But you don't see many 0w-40's from other US manufacturers sold in the US. I can see where it might be useful in Canada, since it's so cold up there in the Great White North.

This Amsoil 0w-40 has high levels of AW additives since it's intended to be used in power sports equipment engines with wet clutches. The ZnDTP is there to provide gear protection in the transmission. Shear stability is critical in these applications, so the oil is pretty shear stable - for a 0w-40.

The last time I checked, xw-40 oils didn't have to meet the API chemical limits for ZnDTP. In fact this is precisely why many folks like using HDEO's in their gas engines.

Buster,

I see more of a correlation between HT/HS viscosity,SAE grades and fuel efficiency. My
best mileage so far has been with the Series 2000 0w-30 and my worse has been with the much thicker Amsoil 10w-40. This oil falls somewhere inbetween as expected. Fuel efficiency is mainly determined on how easily the oil pumps during the warmup phase and it's HT/HS viscosity under steady state conditions.

I'm beginning to think that FM's loose their effectiveness after about 3000-5000 miles.The API fuel efficiency test measures fuel efficiency after 16 hours and 96 hours in an engine on a test stand, so that doesn't tell you how the oil performs over the course of a long service interval.

TS

 

[buster]

quote:

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I see more of a correlation between HT/HS viscosity,SAE grades and fuel efficiency. My
best mileage so far has been with the Series 2000 0w-30 and my worse has been with the much thicker Amsoil 10w-40. This oil falls somewhere inbetween as expected. Fuel efficiency is mainly determined on how easily the oil pumps during the warmup phase and it's HT/HS viscosity under steady state conditions.

I'm beginning to think that FM's loose their effectiveness after about 3000-5000 miles.The API fuel efficiency test measures fuel efficiency after 16 hours and 96 hours in an engine on a test stand, so that doesn't tell you how the oil performs over the course of a long service interval.

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Interesting, thanks Ted. I was surprised to find out this oil had no FM's. Regardless, this is a well built oil and I'm sure many engineers would rather build it this way. Looks similar to a RL formulation. They wouldn't be able to mass market this oil though with the level of AW additives this oil contains. It would end up looking like the AFL 5w-40 if they did. BTW, the wear looks great, I just know that these VW engines tend to show low wear much like Toyotas. The more interesting numbers from this report are the TBN and viscosity. IMO.

 

[TooSlick]

Buster,

Amsoil could have marketed this as their ACEA A3/B4 Euro oil, but the SAE 5w-40's seem to work better in TDI diesels then 0w-40's, and I think you'll see "clean" diesels become a larger part of this market niche in the future. An SAE 5w-40 is also recommended for year round use by almost every Euro manufacturer, so it makes more sense to go that route.

To be honest I thought that this oil would shear like crazy with a VI of 200! So I was sort of shocked when I got the on-line report.

TS

 

[TooSlick]

Bumped to the top, as per a request by PMail....

TS

 

[buster]

This oil wouldn't meet any current API approval with the level of anti-wear additives it has. I guess one could use it for racing....

 

[buster]

Quote:

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AMSOIL AFF is formulated with high levels of anti-wear additives that provide excellent protection for pistons, bearings and gears in transmission containing units, while its shear stable, SAE 40 viscosity delivers a thick lubricating film for an extra margin of protection in hard working engines.

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