For those of you just entering 1:8 scale racing. Just a little story about shock-fluids.

In the beginning of the 80's cars were equipped with small shock absorbers 1/4 of the current size. The shock fluid used was normally a kind of transmission oil. 
These oils always changed in viscosity (thickness) during use and temperature and a stable shock oil was not there. Therefore all kinds of products were tried. 
Even STP oil was used, you then had to warm up your shocks before racing with a hair dryer before you could use them.
Fortunenatly silicone oil was introduced in the mid 80's.
This type of oil has an better constant viscosity over a wider temperature range then other fluids but still is not complete temperature stable!

The thickness of the oil is officially rated in Centi Stokes "Cts".
Centi Poise (nowadays called Pascal per second) is the result of the Centistokes value magnified with the density of the oil.
Normally for silicone oil this value is 0.9875 = almost 1.0

An other known and used American rating is WEIGHT "WT". 
This WT or W rating is a non world standard and is introduced by Associated and not comparable between brands using this W or WT rating.

Thanks to Casper who found this remark on the net about SAE WT:

"Correct measures of viscosity are centi-stokes, N/m^2, or poises, depending on how you define it.
SAE WT is not really a measure of viscosity. The SAE scale was designed for classifying motor oils. For example SAE 30/40 means that the viscoity is one value (30) at one temperature and an equivalent (40) at the engine running temperature. When the number has WT after it this means "winter" so that the oil will have a particular value at I think 0 degrees Celsius.
The main problem with using the SAE scale oil is that each SAE band can encompass a large variation in viscosity. For example one manufacturers SAE 5 can be anothers SAE 10 and both are within limits. Using the SAE scale oil is best only to compare one manufacturer. "

Concerning Cts the thinner the oil (fluid) the lower the number, the ticker the oil the higher the number. 
For normal shock absorber use, this rate may vary between 100 Cts until 900 Cts.
Nowadays we use O-ring sealed diffs, so we can use silicone oil in the diffs instead of thick grease. 
For diffs the rate may vary between 1.000 Cts (loose) up to even 500.000 Cts (very, very, stiff).

Some USA based companies still are using the "WT" weight rating, where Japanese and European companies use the better linear industry standard Centi Stokes or Centi Poise rating. 
A lot off people think that the ratings between the "WT" and "Cts/Cps" ratings are linear but this isn't the case.

If there is a factory that can provide oil for testing we can arrange this to see if the product reaches the specification claimed or convert to Cts!

Which manufacturer use which rating?
Which manufacturers you can use same rating oil?
Only manufacturers using Cts as rating are using a world standard and can be mixed used.
Other ratings like W and WT differ from brand from brand as WT or W is not a world standard!

If you have better information let us know

For shock absorber use, this is the comparison table when using LOSI,  ASSOCIATED and SERPENT some others silicone oil rated in "WT" "W" or are not labeled with a rating but just a number like 30/300

The 50 Cts steps between "Cts" rating are linear, where the 5 "WT" steps used in the "WT" rating are progressive compared to the real thickness of the oil.

No one can tell TEAM TWF8 how "WT" OR "W" rating is measured!!!!! If you know it let us know! info@twf8.ws

We tested this oil supplied by Serpent Benelux on 04-01-2005 in our labaratory and compared them with a calibration oil.of 100 Cts.

Conclusion:
  Serpent oil is way of linear with Cts rating

Use the values above for your benefit and as a guideline.
TEAM Xray has improved their oil line values from December 2006 onwards.
They now have a new silicone oil supplier.
Xray oil provided by TEAM Xray Slovakia

Use the values above for your benefit and as a guideline.

Use the values above for your benefit and as a guideline.
* The value 15 Weights we measured was like water thickness and is probably a filling fault at the factory.
Altough the contents was silicone oil it was to thin for the 15 WT specs and can not be used for the shocks.
Associated oils were provided by Kendall Bennet from A-mainhobbies and Tony Penzincka from Tony Screws

*T he cyan colored values collum are provided by Kurt Menger from Team Assosiated R&D and are the values that will be curerntly mentioned on the bottles to give comparising with Cts values. (18-10-2007)

Use the values above for your benefit and as a guideline.
Trinity oils were provided by Kendall Bennet from A-mainhobbies and Tony Penzincka from Tony Screws

Use the values above for your benefit and as a guideline.
Losi oils were provided byVolker Gerdes from BUGGY-SPORT.INFO

Currently we are measuring our oils with a RHEOMETER.
A sample of such a machine can be found here

This device is able to measure more accurat regardless the viscosity.

From September 2006 we measure all oils with a RHEOMETER.

SILICONE SHOCK OIL AND TEMPERATURE

Although everybody thinks silicone oil is not affected by temperature, we can wake you up out of that dream. 
When the same test is done @ 10 or @ 30 degrees Celsius we get other values!
Test result from our laboratory provid us with the following fist rule:

Below some examples.

To estimate your needed viscosity we made a XLS spreadsheet which you can use for calculating the correct viscosity.
You can download it here.

Team TWF8 special thanks goes to Jacco Koch our Chemicals specialist from The Netherlands for testing the fluids and the pictures.

Click here and see how to mix your silicone shock and diff oils in the right percentages.