RC Car Differential Oils

Shop RC differential oils in a wide range of viscosities for fine-tuning the handling and performance of your radio-controlled car, truck, buggy or racing model. Differential oil is used in gear differentials to control how freely the internal gears allow the wheels to rotate at different speeds.

Choosing the correct differential oil is an important part of RC setup. Different oil viscosities can significantly change the vehicle's acceleration, cornering behaviour, traction and overall handling characteristics.

What Does Differential Oil Do?

An RC gear differential allows the left and right wheels to rotate at different speeds when the vehicle turns. This is important because the outside wheel travels further than the inside wheel during a corner.

Differential oil controls the amount of resistance inside the differential.

Thinner oil:
Allows the differential to operate more freely, providing greater difference in wheel speed.

Thicker oil:
Creates more resistance and causes the differential to act more like a locked or limited-slip differential.

Changing the differential oil viscosity is one of the most effective ways to tune the handling of an RC vehicle.

Differential Oil Viscosity

RC differential oils are available in a very wide range of viscosities, commonly measured in cSt (centistokes).

Common viscosities include:

• 100 cSt
• 200 cSt
• 300 cSt
• 500 cSt
• 700 cSt
• 1,000 cSt
• 2,000 cSt
• 3,000 cSt
• 5,000 cSt
• 7,000 cSt
• 10,000 cSt
• 20,000 cSt
• 30,000 cSt
• 50,000 cSt
• 100,000 cSt and higher

The exact viscosity range available will depend on the manufacturer and intended application.

How Differential Oil Changes Handling

The effect of differential oil depends on whether it is being used in the front, centre or rear differential and on the type of vehicle.

Front Differential

Thicker oil can provide increased front-end drive and affect steering and corner entry behaviour. Thinner oil allows the front differential to operate more freely.

Centre Differential

Centre differential oil is particularly important on 4WD and AWD vehicles. Thicker oil can transfer more power between the front and rear axles, while thinner oil allows more differential action.

Rear Differential

Rear differential oil affects rear traction and cornering characteristics. Thicker oil can increase rear drive and stability, while thinner oil allows greater differential action.

The ideal setup varies significantly between vehicles and driving conditions, so it is recommended to start with the manufacturer's suggested oil and adjust from there.

Differential Oil for RC Racing

Differential oil is an essential tuning tool for RC racers. By changing the viscosity in the front, centre and rear differentials, drivers can fine-tune the balance of the vehicle to suit:

• Track surface
• Track layout
• Grip level
• Tyres
• Weather conditions
• Driving style
• Vehicle setup
• Motor and battery power

A different oil setup may be required for high-grip carpet compared with low-grip dirt, clay or outdoor surfaces.

Silicone Differential Oil

Many RC gear differentials use silicone-based differential oil because it provides consistent damping characteristics over a wide range of temperatures and operating conditions.

Silicone differential oil is available in a range of viscosities, allowing precise tuning of differential action.

Always use differential oil recommended by the vehicle or differential manufacturer.

Differential Maintenance

Differential oil should be checked and replaced periodically, particularly on vehicles that are raced or used frequently.

When servicing a differential:

1. Remove the differential according to the vehicle manufacturer's instructions.
2. Disassemble and clean the differential components.
3. Inspect the gears, pins, seals and bearings for wear or damage.
4. Replace worn or damaged components.
5. Reassemble the differential correctly.
6. Fill with the recommended differential oil.
7. Ensure the oil is distributed evenly through the gears.
8. Check the differential for smooth operation before reinstalling.

Avoid overfilling the differential. Follow the manufacturer's recommended fill level and assembly procedure.