Offset (ET)
How far a wheel’s mounting face sits from its centreline, in millimetres. Higher pulls the wheel inboard, lower pushes it out.
Offset, usually written as ET followed by a number, is the distance in millimetres between a wheel's mounting face and its centreline. A higher number pulls the wheel further inboard under the car; a lower or negative number pushes it outboard.
On a drift car this is one of the most consequential numbers you will choose, and it is the one people most often get wrong - because the right answer changes depending on what else is on the car.
Why it matters more here than on a road car
Fitting an angle kit swings the front wheel through a much larger arc than the factory geometry ever did. An offset that cleared perfectly at standard lock can foul the control arm, the tie rod or the inner arch once the kit is on. On most chassis the usable front window moves out by roughly 8 to 10mm, meaning you need a *lower* number than you could run before - to push the wheel outward and buy clearance on the inside, where the contact usually happens.
The limiting contact point is frequently not the one people expect. It is often the inner shoulder of the tire against the lower control arm rather than anything near the arch.
How to get it right
Each chassis page on this site carries the window that commonly clears on a standard-bodied example, with and without a kit. Those are starting points, not guarantees - ride height, camber, tire profile, which kit you fitted and whether the arches have been rolled all move the answer.
The cheapest way to find your real number is a spacer on wheels you already own, cycling to full lock with the suspension loaded rather than on a jack. A spacer is also the standard trackside fix when something rubs.
Bolt patterns matter too
Offset is not the only compatibility number. The chassis in our catalogue span 4x100, 4x114.3, 5x100, 5x114.3 and 5x120, which means a bargain set of used wheels from one platform frequently will not physically fit another. Check the pattern before the offset.
Questions
Lower or higher offset for drifting?
Usually lower than factory, especially with an angle kit, because you need clearance on the inside of the wheel. Too low and the risk moves to the outer arch and the wheel bearing, so there is a window rather than a direction.
Are spacers safe?
Used correctly, with the right thickness, correct extended studs where needed and proper torque, they are widely used. They do change how the bearing and studs are loaded, so they are not a free lunch - but as a way to test clearance before buying wheels they are the standard approach.