Wheel spacers are a popular upgrade for improving stance, enhancing handling, or creating clearance for performance brakes and suspension components. But not all spacers are the same—two main types exist: slip-on and bolt-on wheel spacers.

While both serve the same purpose (pushing your wheels outward), they work differently and suit different applications. Choosing the right type is essential for safety, fitment, and performance.

Here’s a clear breakdown of the differences, advantages, and when to use each one.

What Are Wheel Spacers?

Wheel spacers sit between the wheel and the hub to move the wheel outward. This increases the vehicle’s track width, providing benefits like:

• Improved stability

• Better wheel arch fitment

• Clearance for brakes, suspension, or wide tyres

• A more aggressive stance

Slip-on and bolt-on spacers achieve this in different ways.

Slip-On Wheel Spacers

What They Are

Slip-on spacers simply slide over your existing wheel hub. The wheel is then mounted over the spacer using longer wheel bolts or studs.

How Slip-On Spacers Work

1. Spacer slides onto the hub

2. Wheel slides onto the spacer

3. Longer bolts or studs secure the wheel

There are no built-in studs in this type of spacer.

Best Thickness Range

Slip-on spacers typically work best for:

• 3mm–10mm (thin spacers)

• 12mm–15mm (medium)

Beyond this, bolt length and hub centering often become an issue.

Advantages of Slip-On Spacers

Ideal for fine-tuning stance
Lightweight and simple
Perfect for small to medium fitting adjustments
Cheaper compared to bolt-on spacers
Great for cars that use wheel bolts (common in Europe)

Disadvantages

Require longer wheel bolts or studs
Can cause vibration if not hub-centric
Not suitable for very large thicknesses
Can reduce hub engagement if too thick

Bolt-On Wheel Spacers

What They Are

Bolt-on spacers fasten directly to the hub using your existing wheel bolts, and your wheel then attaches to studs built into the spacer.

They are essentially an extension of the hub.

How Bolt-On Spacers Work

1. Spacer bolts to the hub

2. Spacer becomes a solid mounting surface

3. Wheel mounts to the spacer using its built-in studs/bolts

This makes them more secure for larger spacer sizes.

Best Thickness Range

Bolt-on spacers are recommended for:

• 20mm–30mm+

• Thick fitments where long bolts would be unsafe

Advantages of Bolt-On Spacers

Strongest and safest option for large thicknesses
Maintain full thread engagement
Reduce hub stress compared to thick slip-on spacers
No need for longer wheel bolts
Ideal for performance cars and wide aftermarket wheels

Disadvantages

More expensive
Heavier than slip-on spacers
Require accurate installation
Need enough clearance in the wheel for bolt heads

Slip-On vs. Bolt-On: Which One Should You Choose?

Choose Slip-On Spacers If:

• You only need small to medium thickness

• You want subtle stance correction

• Your primary goal is appearance (flush fitment)

• You’re not drastically altering wheel offset

• Your setup uses wheel bolts and has good hub length

Choose Bolt-On Spacers If:

• You’re using thick spacers (20–30mm+)

• You need extra clearance for wide wheels or big brakes

• You want maximum strength under high performance

• Your vehicle uses wheel studs

• You want full thread engagement without longer bolts

Are Both Types Safe?

Yes—when used correctly with:

• High-quality, hub-centric spacers

• Correct bolt or stud length

• Proper torque procedures

• A clean hub mounting surface

The danger comes not from the type of spacer, but from incorrect installation or cheap, poorly manufactured spacers.

Final Thoughts

Slip-on and bolt-on spacers both widen your track and transform your fitment, but they’re designed for different situations. Slip-on spacers are perfect for small to medium adjustments, while bolt-on spacers are the safest choice for thicker fitments and performance applications.

Looking for wheel spacers? Click here and use our simple vehicle search tool to find suitable spacers for your car.