There seems to be a lot of debate about what brand of oil to use in shocks and differentials. While silicone oil is recognized as the best for RC due to its ability to resist changes in viscosity due to temperature fluctuations, the labeling can be misleading. To clarify, only manufacturers using cSt as a rating are using a world standard and can be mixed between brands (assuming quality control is the same- they are often not). Other ratings like W or WT (often referred to as “weight”) differ from brand to brand and are not a world standard. Fortunately, some brands that use this labeling also print the cSt rating in small print for convenience. Among racers there’s always been rumors and speculation about what to use, so we’ve put together this chart to help compare oils from TLR and Team Associated- two common brands used in off-road racing.
The 50 cSt steps between “cSt” rating are linear, where the 5 “WT” steps used in the “WT” rating are progressive compared to the real thickness of the oil. Keep in mind this is only an estimate since the method for measuring depends on the manufacturer among other factors. As you can see below, Team Associated converts their oil slightly different than the chart above. The best recommendation is to stick with one brand to eliminate the issues of variance and tune accordingly.