Blackstone Labs is an excellent choice! They are very consistent, and give excellent turnaround time. Often times people will get their results emailed to them in less than a week after sending out the sample.

If any of you guys decide to get your oil analyzed, post the results on here so we can look them over.

IMHO stay away from any Redline fluids

I know 1st hand, when my ZR-1 was almost brand new I was talked into by that vendor to test their fluids and oils.
Being this $60,000 car was new and in warranty the vendor ASSURED me there would be no backlash in using their products and would not harm the warranty.

All was BS, the motor oil would seep through cam covers, even travel up bolts and leak out.
The trannie fluid within a few months hot spotted the syncros and when I took it to a dealer and GM saw the redline they VOIDED the whole warranty and I was stuck paying out over $5,000 to get rrannie fixed.
I took GM to court over the warranty and lost the case for GM proved that redline was harming their cars and cost was another $10,000 in lawyers fees

I contacted Redline and they refused to even look at the car even though they are based local to me.
I contacted ZF who makes the trannie and told me they had seen so many failures due to Redline that they also woould void warranty if that vendors fluids were used.

I contacted SAE to find that after all these years of redline making hugh profits that they still never had their products SAE tested to be certified and also get the StarBurst approval.
They said the makeup of those products have stuff in them that is high cleaner and once old fluid is taken off parts the redline products over time and heat break down and in synros fluid then was not staying on syncros and then caused them to hot spot.
That crap may be great for racing where engine is broekn down after each event but for long term use is junk.
Clearly any vendor who does not want to get SAE tested wants to hide something for being tested and approved would be a marketing plus.

I know of many other Corvettes that have had damage using that brand.

I also know Mobil 1 people and have seen test results where engine ran for over 200,000 miles, engine broken down and no wear found.

I have used Mobil 1 since 1994 in street and in long distance high speed racing and never once had any failures so as they say if its not broke do not change it and no one has proved using a non certified fluid/oil has any positives and in fact costs twice what Mobil 1 costs and if your car is still under warranty stay with OEM approved filuds/oils.

API Licensing - Passenger Cars - What is it?
An API (American Petroleum Institute) license indicates that a specific motor oil formulation has passed the minimum performance standards as defined by a series of laboratory bench, physical, chemical and engine tests. These tests were selected and minimum performance standards were set by the API Lubricants Committee to address specific areas such as engine wear, deposits, fuel economy, emissions, etc. The committee is comprised of representatives from automobile, oil and additive companies. The current specification is SJ/GF-2, and in July 2001 the first use of SL/GF-3 will begin.

Costs
The cost for running a test program for a single passenger car motor oil formulation is from $125,000 to $300,000, depending on if the formula passes the tests the first time through or requires multiple test runs or formula modifications to achieve a passing average. (That amount goes to $275,000 to $500,000 for a Heavy Duty Diesel licensing program on a specific formula.) Once that testing is complete and the formula has passed all of the minimum requirements, it can be licensed for $825 per year for non-members and $625 per year for members. There is also a small royalty fee per gallon sold for all gallons over one million. The length of time between new specifications is now approximately 2 to 3 years, which does not allow a great deal of time to recover testing costs.

Who Licenses What Formulas?
Additive companies, such as Lubrizol, Ethyl,, Infinium and Oronite, develop licensed formulas that they offer to oil companies to re-license. It is inexpensive to re-license one of these formulas, and the majority of oil companies choose to do this to avoid the costs associated with testing. This, however, tends to commoditize the market. The same chemistry is being sold under many brand names. Most of the major oil companies do have their own proprietary formulas developed, tested and licensed. All of AMSOIL INC.'s lubricant formulas are unique and proprietary.

Flexibility In Manufacturing An API Licensed Formula
API licensing was originally developed for mineral based oils, and it affords these oils more flexibility than synthetic oils.

Mineral oils comprised of Group I and Group II petroleum basestocks may use a simple program called basestock interchange for added flexibility in manufacturing and purchasing. Interchange means that by completing the proper paperwork and running a few minor engine tests an oil company can choose to buy these petroleum basestocks from many different suppliers. This ensures adequate supply and competitive pricing. However, basestock interchange for Group III and V synthetic basestocks is not allowed. For example, if a formula was tested with an ester (Group V) basestock from a specific supplier, then anyone blending that formula must buy only that supplier's ester. Complete engine testing would need to be performed on the formula using another supplier's ester before an oil company could buy it from that alternative supplier. This additional testing is normally not performed because of the associated costs. This inflexibility makes it very difficult for synthetic lubricant manufacturers to negotiate prices with synthetic basestock suppliers. Click HERE for more information about Group I through Group V basestocks.

There is also something called viscosity grade read-across. Fortunately, this applies to both petroleum and synthetic basestocks although the better cold temperature performance of synthetics makes it more difficult to achieve in some situations. (That's another whole story.) What this means is that if you properly formulate the lubricant for which you have run all of the API tests, there are guidelines that allow you to use that same formula to make 0W-30, 5W-30, 10W-30, etc. viscosity motor oil.

Finally, there is a rule for substitutions in the CMA (Chemical Manufacturers Association) code of practice that allows a small degree of flexibility for all formulas. It allows a company to change the percentages of components in the formula by varying amounts from the original formula with limited testing and paperwork requirements. For example, if the licensed formula used 10% of a certain V.I. improver, you would have the ability to utilize from 9% to 11% of the same V.I. improver for your formula.

Key Limitations For API Licensed Formulas
Phosphorous content - .10% maximum
API SL; 0W-20, 5W-20, 0W-30, 5W-30, 10W-30 viscosity grades, only)
NOACK volatility - 15% maximum

Click HERE for an explanation of NOACK Volatility

The prevalent sources of phosphorous in motor oils are additives called zinc dithiophosphates (ZDTPs). Currently, these versatile additives act as oxidation/corrosion inhibitors and aid in the ability of a lubricant to reduce wear. The automobile manufacturers, however, have demanded that lubricants contain a maximum of only .10% phosphorous. Their reason is that some manufacturers believe that higher phosphorous content levels will poison the catalytic converters on their cars before they reach 150,000 miles, which is the number of miles that their vehicles will be required to pass EPA emission standards. There has not been total agreement within the automotive and lubrication industry about whether phosphorous levels over .10% actually do harm catalytic converters in the long run. What they have failed to make allowances for is the NOACK volatility of an oil.

The maximum allowable NOACK volatility percentage for the new SL/GF-3 passenger car motor oil specification is 15%. Most of AMSOIL motor oils are in the 5% to 8% NOACK volatility range. Studies have shown there is a correlation between NOACK volatility, oil consumption and the amount of phosphorous from motor oil that will end up in the exhaust gasses.

Therefore, oils with higher levels of phosphorous but with low volatility, such as AMSOIL motor oils, present no more risk to catalytic converters than low phosphorous oils with higher NOACK volatility. This has also been demonstrated for years in actual application through state mandated exhaust gas testing on our Dealers' and customers' high mileage vehicles using AMSOIL synthetic motor oils. State inspectors are continually amazed at the low emissions levels generated by vehicles using AMSOIL products. So much for poisoning catalytic converters.

AMSOIL INC. has determined that the reduced wear and extended drain intervals achievable with phosphorous levels higher than the API limit of .10% are real benefits for the consumer, and pose no risk to catalytic converters. AMSOIL motor oils, except for the API licensed XL-7500 5W-30 and 10W-30 viscosity grades, all have greater than .10% phosphorous levels, and therefore, cannot be API licensed.

Why Some AMSOIL Synthetic Motor Oils Are API Licensed And Some Are Not
1. Full API licensing puts AMSOIL INC. in an inflexible position. Not only would we find it necessary to buy formula components from specific vendors and be at the mercy of their pricing, we would not be able to make any major improvements to the lubricant formulas for 2 to 3 years, without new testing and the associated costs. To solve this problem, the API must establish basestock interchange guidelines for synthetic basestocks just as they have for other basestocks, as well as develop interchange guidelines for other components too.

2. Full API licensing would impose strict phosphorous limitations on our motor oils. This limitation is the main reason most AMSOIL motor oils are not API licensed. AMSOIL INC. currently disagrees with this limitation and feels strongly that the reduced wear and longer oil and additive life achieved through higher levels of properly balanced phosphorous content is more important than the arbitrary API phosphorous limit that does not give any consideration to the NOACK volatility level of an oil. When chemistry is developed that will provide superior engine wear protection with reduced phosphorous levels, or Noack volatility considerations are put in place, then the phosphorous level will become a non-issue.

Several months ago, Hib and I performed a tear down on
his ZF S6-40 transmission which was lubricated by Redline
Lightweight Shockproof.
The reason for tear-down of Hib's ZF S6-40 6-speed was for
creating process document and to check out the overall condition
of the unit.

UNIT CONDITION:
The component wear-characteristics appeared to be excellent
in all aspects. Significant miles were put on this unit to the point
where it was obvious that Redline Lightweight Shockproof
lubricant excels in the longevity provision department.

CONCLUSION:
Although I can not yet comment on the shift-effort performance,
the preventive-wear characteristics of Redline Lightweight Shockproof
are excellent. For the benefit of the new member's, we (ZR51 Performance)
rebuild balance/blueprint these transmissions on a near to daily basis.

I would like to add some insight upon the topic of oil selection in the
ZF S6-40 transmission. (by Bill Boudreau ZR51 Performance)

SYSTEM LEVEL:
The key component(s) in this transmission is undisputably the
synchronizer(s).
The synchronizer(s) can be classified as a wear-range component.
The key support system of this transmission is the hydraulic clutch system.
Clutch hydraulic system anomalies have a direct impact on the performance
and life expectancy of the synchronizers.

COMPONENT LEVEL:
With each gear shift, phosphorus-bronze particles shed from the
synchronizers into the transmission oil. Based on shifting technique and
operating conditions, usefull wear-range of the synchronizers is expended.
This attributes to the presents of phosphorus-bronze particles suspended
in the transmission oil. Most of these particles end up settleing in various
ancilliary cavities throughout the transmission case. Regardless of the
brand and
quality and oil used in this transmission, levels of phosphorus-bronze
particles
suspended in the oil can be expected to increase throughout the life-cycle
of each
oil change.

ABSTRACT:
"Shiftability-performance" longevity of the synchronizer(s) is the number
one concern
when seeking a suitable lubricant for the S6-40 gearbox. Given the condition
that the
clutch hydraulic system is performing at 97%+ efficiency, the factory fill
5W-30,
Castrol RS 10W-60, and Redline MTL/LSP are all very suitable for use in
these
transmissions.
I must reserve judgement on selecting which oil is the best one to use based
on
the number of factors involved with providing equal conditions at the system
and component
level when performing such a comparison test.

A DIFFERENT VIEW:
With all of this in mind, let's address the issue of duration between oil
changes.
ZF Industries recommends 20K mile increments between changes.
We won't even mention what GM recommends.

With a 50/50 mix of highway and city driving, I found that changing the
transmission
oil every 8K-10K miles greatly reduces the phosphorus-bronze deposits which
collect
on the inner surface (splines) of the 4 sliding sleeves (1st/2nd, 3rd/4th,
5th/6th, and Reverse).
Each sliding sleeve acts as a centrifuge seperating the heavier
phosphorus-bronze
particles from the transmission oil.

The longer the transmission oil change cycle is, the higher the percentage
of
suspended phosphorus-bronze particles which are suspended in the oil.
This condition can lead to reduced performance of sliding sleeve actuation
and shifting
performance.degredation.

The copper based phosphorus-bronze material of the synchronizer rings cannot
be exposed
to sulfer based oils such as differential lubrication. The only acception to
this rule is that
corrosion inhibitors be present in the oil's composition.

In 4 seperate instances, I observed a glaze build-up on the
phosphorus-bronze surfaces them self
with units using Mobil-1 oil.

Zroners-
After my post in the recent "Recommended Maintenance" thread about rear
axle and transmission lubricant change intervals and my recommendation of
Red Line 75W90 rear axle lube and MTL transmission lube, I received a
flurry of emails asking about the Red Line Heavy and LightWeight
ShockProof lubricants many have read me endorse often here on the list.

The original question was asked about the recommended change interval for
the rear axle and transmission in a ZR-1 and the appropriateness of the
OE GM lube and OE GM friction modifier (limited slip "additive").
Typically, those questions are asked by persons who usually do not
subject their cars to severe duty and are conservative on the lubricants
they choose. In that case, I usually suggest the rear axle lubricant
recommended by Red Line for clutch- and cone-type limited slips, and
that's 75W90 Gear Oil. Same is true of Red Line MTL for the ZF S6-40
six-speed manual transmission.

That said, my personal choice for lubrication of the rear axle and
transmission in my ZR-1 and most of my other vehicles is the Red Line
ShockProof series. Shockproof lubes are better, IMO, for severe duty
applications and have two advantages over conventional petroleum-based
lubes: a gel-based lubricant technology and a calcium-based extreme
pressure additive package.

ShockProof Gear Oil provides unequaled protection for high-performance
differentials and transmissions that are heavily loaded or are subjected
to severe shock loads. This lubricant technology is different from that
in conventional gear lubricants in several ways. The viscosity
characteristics are significantly better. Gear teeth need high viscosity
at high temperatures to prevent metal-to-metal contact and a low
viscosity when cold to reduce fluid friction. The ShockProof chemistry
significantly reduces the thinning effect of high-temperatures.

The Heavy ShockProof can be rated as a 75W250 Gear Oil, but has the lower
internal fluid friction of an SAE 75W90. The LightWeight can be rated as
a 75W140 Gear Oil, but has the lower internal fluid friction of an SAE 30
motor oil. The SuperLight can be rated as a 70W90 Gear Oil, but has the
lower internal fluid friction of an ATF. These ShockProof lubricants
provide much greater viscosity in the thin layers between the gear teeth,
but have very low internal fluid friction, which means very little power
loss for the protection and lubrication achieved.

In 1996, I began a test program in cooperation with Red Line Oil to
evaluate the performance of Heavy ShockProof in the rear axles of
street-driven, high-performance cars. There was some concern on Red
Line's part about doing this as the product had been designed as a
competition-only lubricant and had never been used in a road vehicle. To
date, I've run HSP 31269 miles in the Dana 44 rear axle in my ZR-1, 4928
mi/5 yrs in the Chevrolet rear axle in my 71 Coupe (530hp engine), 33,000
mi. in the 12-bolt Chevy rear axle in my Chevelle and 46500 mi. in the
8.5-in. Chevy rear axle in my 99 Blazer. At lube changes a sample of the
lube is spectrographically analyzed. To date, there have been no problems
with wear. The spectrographic analyses have always come back nominal.

In 1998, enthusiastic about my results with HSP in rear axles, I talked
Red Line into a test program using Lightweight Shockproof in manual
transmissions. I put LSP in both the ZF six-speeds in my ZR-1 (19021 mi)
and my Malibu (9282 mi), in the front-drive transaxle of my Chevy Beretta
(26152 mi) and, when I bought it in June of 99, in the ND 3500
five-speed in my Blazer (46,500 mi). Again, there have been no problems
with the transmissions in those cars and the spectrographic analyses have
come back nominal. Additionally, in January of this year, Bill Boudreau
disassembled my Malibu's ZF and was amazed at the low level of wear on
all its parts. He's become a believer in Light Shockproof or, as he calls
it for its peculiar, pastel blue color, "Martian Blood."

Based on the fact that Red Line suggests the Light Shockproof rates at
75W140 but flows like a SAE30 engine oil and SuperLight rates like a
75W90 but flows like an ATF, my newest "Shockproof on the street" test is
to run a rear axle on LSP and a manual trans on SLSP. I bought a 2001
Camaro last spring and at the 5000 mile mark switched the engine to Red
Line 10W30 and the trans from the OE ATF to Red Line D4 ATF. At 6125 mi.,
I replaced the OE rear axle lube with Red Line 75W90. These lubricants
were used for a dyno test of Red Line's normally-recommended lubricants
for those applications and there was about a 2% gain in power. At the
9400 mi. mark, I put Light Shockproof in the car's axle (Zexel-Torson
limited slip) and SuperLight in the car's five-speed transmission. The
point of this test is to see how the lower viscosity ShockProofs will
perform in a road car. I'm considering trying the SuperLight in the ZF in
my Malibu.

Lastly, it's important to note that Red Line Synthetic Oil Corp. does not
currently recommend use of the Shockproof lubricants in road vehicles
but, neither do they say not to use them in road vehicles. I suspect that
will change some day, but given our litigious society and the
conservatism that permeates the lubricant industry, it may be a while
before it does.

What Red Line does recommend for rear axles and many manual transmissions
(the ZF included) are 75W90 Gear Oil and MTL.


cYa
Hib Halverson