Many beginner hobbyists find it difficult to choose oils for their RC cars. The manual doesn’t always have information on oil properties. There are many things to consider when choosing shock oils and in this article, we’ll go over our recommendations for a basic setup.

When picking oils for the damping, there are several things to considering, including the weight of the car, the size of the absorber, the stiffness of the spring, how many holes are on the piston, etc. In this article is assumed that cars tend to have same default adjustments when taken out of the box.

The thickness of the oil is stated in cst or WT. The greater the number, the thicker the oil. cst and WT values aren’t directly comparable, so it’s good to stick to one of them and always get the oil from the same brand. That way it’s easier to keep track of the thickness of the oils.

Below you’ll find our recommendations for different categories. The rear damping will be softer by default (smaller cst value)

1:10 Touring 4WD

• Recommendation 400cst / 35wt

Touring cars differ from the others in that they usually have the same oil both in the rear and the front. However, the basic principle regarding oil choice is the same as with other cars. With thinner oils you’ll get a better grip for your car, but turning becomes lazier and the car will roll more in curves. The most common oils for cars in this category are in the 350–500 cst range. In Touring cars, the spring travel is significantly shorter so there’s also less travel space for damping compared to, for example, off-road cars. Careful assembly of the shocks and identical results are much more important in a Touring car (very sensitive to adjustments) compared to off-road cars.

1:10 Buggy/Short Course 2WD

• Recommendation 300 and 350cst  25wt and 30wt

Front: 300–350cst / 25-30wt
Pick the thicker oil for higher traction and thinner for lower traction. Thinner oil improves grip on slippery track while steering becomes lazier. Thicker oil makes steering faster and more accurate.
Rear: 250–350cst / 20-30wt
Choose thinner oil for a better grip in the rear. The result is the same as in the front – thinner oil improves the grip but the rear of the car easily becomes more “nervous” when using thin oils. It’s good to bear in mind that the damping should be enough to not let the rear bounce. If that happens, switch to thicker oil. In general, the rear is adjusted to have a softer damping for a better grip.

1:10 Buggy 4WD

• Recommendation 350 and 400cst / 30wt and 35wt

Front: 350–450cst / 30-35wt
Thinner oils for driving in low-traction tracks. In case more accuracy is desired, you can try thicker oil. You can also consider trying 500 cSt if you drive on high-traction surfaces like mat or asphalt.
Rear: 300–400cst / 25-35wt
On low-traction surfaces, soft damping improves grip, but there’s a risk of the rear becoming “nervous”. In that case, I’d recommend increasing damping. Softer damping for the rear.

1:10 Short Course 4WD (newer models, for example Tekno)

• Recommendation 400cst / 35wt

Front: 350–450cst / 30-35wt
Depending on the traction, for slippery tracks, 350 cst, and for high-traction tracks, 450 cst.

Rear: 350–400cst / 30-35wt
To improve grip in the rear, pick thinner oil and if driving on high-traction surfaces, pick thicker oil.

The newer short-course cars have pistons with a large diameter and they can run on thinner oils that provide sufficient damping. See, however, that the car doesn’t dive at bumps or when landing. If the rear starts to bounce, you may have to improve the damping.

1:8 Buggies and Truggies

• Recommendation 450 and 500cst

Front: 400–600cst /35-50wt
Depending on the bumps and jumps at the track, thinner oils can be used in the front if better grip is desired. Landing after jumps and bumps require good damping, so you might have to choose stiffer damping at the expense of grip.

Rear: 350–500cst / 30-40wt
The same rules apply here – soft damping improves grip but the risk involved is that the rear might start to bounce and the car might dive when landing. As a general rule of thumb, the damping should be softer in the rear than the front.

The cars are much heavier in the 1:8 category compared to those in the 1:10 category and thus it’s important to have the right amount of damping in these cars. With heavier cars there’s a greater risk of diving at bumps and when landing after jumps. Too stiff damping in the front results in under-steering and if the damping is too soft in the front, the front will dive when braking. By softening the damping in the rear, you’ll achieve better grip when turning but make sure the damping is sufficient for landings.