No idea what the numbers on this Amsoil chart mean

[TeeDub]

The viscosity index is a measure of the change in viscosity, measured between 40C and 100C. The higher the #, the less the viscosity of the oil changes over that temp range. You can take this data and assume how the oil will behave at temps < 40C and > 100C, but only to a degree. The reason is that the relationship between oil temp and viscosity is "nonlinear". That is to say it's actually a curve and not a straight line. For example, if you look at these specs for the Amsoil 0w-30 and 5w-30, you see the VI's and the viscosities @ 40C are almost equal. However as you cool both oils to temps below freezing, the 5w-30 will thicken slightly more than the 0w-30. If you heat both oils to temps >> 100C, the 0w-30 will thin a bit more slowly.

It is problematic to run any oil longer than 15,000 miles in a gas guzzling V-8, with a relatively small 6-7 quart sump. The reason why the Germans can do it is that their V-8 engines typically hold 9-11 quarts of oil. A look at "Tooslicks" OCI Formula(tm) tells the tale:

OCI(miles) = (C*)(mpg)(sump-qts)(cubic inches/Hp)

where C* is an emperically derived constant, that depends on the basestock and additive chemistry of a particular oil. For Amsoil you would generally use a C* of 125, for example.

work the numbers for a V-8 with a 6-7 quart sump and you can see how difficult it is to run long oil change intervals in relatively inefficient, large displacement engines.

TD

 

[AndyH]

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Also, would one want to see a higher TBN over a lower TBN?

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Generally speaking, yes.

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Also, (mind reader) thanks for telling me what a 'UAO' is. A previous poster mentioned that... and I thought maybe they mispelled 'UFO' or somesuch. How much does that run ($$), and what results is one looking for? Particle count maybe?... I would think that is more a function of the filter.

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Blackstone Labs is a BITOG site sponsor and a popular lab for UOA's. Request a free sample bottle here:
http://www.blackstone-labs.com/free_test_kit.html

If you really want the assistance of a pro to interpret your UOA results, Terry Dyson of Dyson Analysis comes highly recommended by those here on BITOG that use his services. Dyson Analysis is also a BITOG site sponsor.
http://www.dysonanalysis.com/

 

[TimVipond]

Blakinspace - These are the oils the AMSOIL website recommends for your car. Since you are under warranty, I'd stick with one of these and forget about the diesel oil:
Engine Oil
Grade 1......API*
Series 2000 Synthetic 0W-30 Motor Oil
SAE 5W-30 Synthetic Motor Oil
SAE 5W-30 XL Synthetic Motor Oil
and with your driving description I'd pick the 5W30 with the AMSOIL filter and change both at 25,000 miles or once a year, whichever comes first. AMSOIL has made that recommendation for 35 years for millions of customers driving billions of miles with thousands of used oil analysis, so I figure they know what they are doing.

 

[427Z06]

Instead of using equations constructed from star charts by the equivalent of an oil astrologist why not use something based on real science to determine OCIs, namely the GM OLM system? You do have the GM OLM system on this vehicle, correct?

The GM OLM system is a much better indicator of OCIs since it takes in account not only the particular engine (DOD in this case) and the vehicle it's installed in, but also your climate and driving patterns. One procedure that might be used is to note when the OLM says your due for an oil change and then add 50% more miles (assuming you have the appropriate Amsoil installed). Reset the OLM, drive 50% more miles, then send the sample in for an UOA. Given the results from the UOA, you can then adjust the percentage of miles you add to the OLM triggered miles while also building in a safety margin. Reset the OLM again when you actually change the oil.

This method will have the advantage of adjusting the OCI to changes in driving patterns and climate/seasonal changes.

Pablo will fix you up with the proper Amsoil you desire. He comes highly recommended.

 

[blakeinspace]

fascinating.

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OCI(miles) = (C*)(mpg)(sump-qts)(cubic inches/Hp)

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OCI miles = 125 * 20mpg * 6qts * 325cu" / 303hp
drumroll...
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16,089.10891089108910891089108910891089

don't think my odometer is quite that accurate!
Regardless the formula, it just sounds like running a 15,000 OCI with the EAO Filter is a good idea. Frankly after years of running 5,000 miles OCI's with Valvoline it feels wrong to think about running without fresh oil to 20,000 and beyond.
Unlike some folks, I can put a dollar figure on peace of mind... even if it is a placebo effect.

 

[blakeinspace]

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Instead of using equations constructed from star charts by the equivalent of an oil astrologist why not use something based on real science to determine OCIs, namely the GM OLM system? You do have the GM OLM system on this vehicle, correct?

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Hi. My name is blake. I am a Leo. My moon is in the 7th house when I do an oil change...
I don't think Teedub's (TooSlick) formula was claimed to be oil code. Like in Pirates of Carribean... "More of a set of guidelines, if you will." Whatever it is... it made for a fun time waste. And yes, the car has GM Oil Life Monitor.

For funsies... here is my Fiero.

OCI = 125 * 21 * 5 * 172 / 135
16,722 miles.

Regardless what the GM OLM says, doing like was suggested twice now, about getting an UOA around 10,000 miles sounds wise. I clicked on the earlier link, and it looked like it was only $20, and you'd get some good info. Like I said, legitimate dollar value for peace of mind.

I was looking for answers on how to read that data, and you guys really helped me out. Moreover, I got some advice on what oil to use and time between OCI, and how to determine what is labratory best for my vehicle.

 

[Dick in Falls Church]

To put it in simple terms:
My son-in-law was running AMSOIL 10W-30 in a Saab Turbo. When the Series 2000 0W-30 came out, he put in a batch (cost him nothing, since he was here). He called a couple months later and said he was consistently getting 50-60 more miles before the red light came on telling him to get gas.

Now that was a while ago. Both oils have been reformulated at least once, probably a couple times.

at any rate, in my opinion, based on about 29 years of using and selling AMSOIL, the 0W-30 is a better oil. It has more friction modifiers, and different bases blended together.
It will hold up longer, and usually give either better fuel economy or better performance (and these are often mutually exclusive). At any rate, that's what I have in all my cars, and I figure it is worth the extra $10 a year per car.

 

[427Z06]

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Hi. My name is blake. I am a Leo. My moon is in the 7th house when I do an oil change...
I don't think Teedub's (TooSlick) formula was claimed to be oil code. Like in Pirates of Carribean... "More of a set of guidelines, if you will." Whatever it is... it made for a fun time waste.

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You have to understand that I like and respect Teddles. You also have to understand that I like to give Teddles a hard time whenever the opportunity arises.

 

[TeeDub]

I use star charts and Terry Dyson uses Tarot cards - I don't see much difference in that...

My formula is supposed to be a ROM (rough order of magnitude), estimate of the OCI you can run in a particular application. For engines that don't have an OLM, it actually works fairly well, as it takes into account the key variables that determine oil life. The GM OLM works essentially the same way, but I'm guessing it costs slightly more to develop.

In this case the OCI Formula generated a maximum OCI of 16,700 miles, which is not far off the Amsoil Severe Service recommendation of 15,000 miles. Seems about right....

TD

 

[Pablo]

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To put it in simple terms:
My son-in-law was running AMSOIL 10W-30 in a Saab Turbo. When the Series 2000 0W-30 came out, he put in a batch (cost him nothing, since he was here). He called a couple months later and said he was consistently getting 50-60 more miles before the red light came on telling him to get gas.

Now that was a while ago. Both oils have been reformulated at least once, probably a couple times.

at any rate, in my opinion, based on about 29 years of using and selling AMSOIL, the 0W-30 is a better oil. It has more friction modifiers, and different bases blended together.
It will hold up longer, and usually give either better fuel economy or better performance (and these are often mutually exclusive). At any rate, that's what I have in all my cars, and I figure it is worth the extra $10 a year per car.

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On paper maybe. In reality, not so much. ASL in equal at the very least up to about 10-15K. Then there is the price.

If someone gets the MPG gain, a gain the offsets the purchase price, then there you go. I haven't seen this gain, but that's me.

Honestly, I'm not impressed with either at the 20K mark well at least the old formulas. The new formulas look fairly awesome in wear, solids growth and viscosity retention - but there is that pesky TBN.

So what does this mean? ASL is indeed better.

 

[TeeDub]

If you buy the Series 2000 in gallon containers,, ie "TSO-1G" (1 gallon) or "TSO-04" (a case of 4), it runs about $2.00/qt than the regular 5w-30 or 10w-30. This amounts to an extra $10.00-$12.00 annually for the oil and you will typically save at least this much just in fuel savings compared to running a 5w-30/10w-30 - particularly if you do any significant short trip driving in cold weather.

I also like the S2000 MUCH better for turbocharged, gas engine applications like the 1.8L/2.0L/2.7L, VW/Audi engines. It is really in these type of severe service applications where you see that the S2000 holds up better with regards to TBN retention, lower oil consumption and reduced oil temps.

The Amsoil 5w-30 is a fine product, but it won't last as long as the S2000 in most applications....

TS

 

[buster]

For most cars I think the new ASL chemistry is tought to beat, however, in some cars S2k does perform better. Two friends of mine reported lower engine temps, one in a Corvette and the other an Audi.

Amsoil also states in the product literature that S2k has a better chemistry for dealing with high temp. deposits. (Comparison was based on SL ASL though)