Many RC cars today use oil filled diffs, and depending on the car there might be one, two, or three of these in a car. Differentials play an important role in a car, so it is therefore important to rebuild your diffs regularly. You can also gain a lot by adjusting the diff action by changing oil viscosity.
High quality silicone diff oil will stay consistent in different conditions, so you should always choose a quality brand. At EuroRC we offer high quality diff oil from Hudy, Arrowmax, Team Corally ,Team Associated and Traxxas.