If you have spent any time browsing for new wheels for your RC car, you have likely stumbled upon a mysterious number buried in the product description. It might read something like “+3mm” or “-2mm”. This number is the offset, and while it might seem like a minor technical detail reserved for setup geeks, it is actually the magic ingredient that dictates the entire stance and handling character of your vehicle.
At its simplest, wheel offset is the measurement that describes where the wheel sits in relation to the hub of the car. More specifically, it is the distance between the mounting surface of the wheel—the flat part that bolts against the hex hub—and the exact centerline of the wheel itself. This measurement determines whether your wheels tuck neatly under the body or poke out aggressively beyond the fenders.
To visualize this, imagine looking at a wheel from the front, as if you are peering down the length of the car. Draw an imaginary line vertically through the exact middle of that wheel, splitting it into two equal halves. That is the centerline. Now, look at the mounting surface, the part that actually touches the hex adapter. If that mounting surface sits perfectly aligned with the centerline, you have zero offset.
The magic happens when that mounting surface moves. If the mounting surface is pushed further outward, meaning it sits closer to the outside edge of the wheel, that is positive offset. This shifts the entire wheel inward, tucking it deeper into the wheel well. You see this a lot on touring cars and vehicles designed for precision on pavement, where you want the tires neatly hidden under the bodywork for aerodynamic efficiency and a clean look.
When the face of the wheel hex hub is aligned with the center of the wheel, this is a zero offset.
Negative offset gives the car a wider stance (hex hub closer to the wheel shaft), and vice versa.
If the mounting surface moves inward, shifting closer to the back edge of the wheel, that is negative offset. This does the opposite, pushing the wheel outward, away from the chassis. This gives the car a wider stance, a broader track, and that aggressive, beefy look where the tires stick out past the fenders. This is the territory of monster trucks, crawlers navigating off-camber trails, and bashers where stability is king.
The impact on handling is profound. When you push the wheels outward with negative offset, you are effectively widening the track of the vehicle. This instantly makes the car more stable, reducing body roll and making it harder to flip during high-speed cornering. It plants the tires further apart, creating a solid foundation. The downside is that this wider leverage can put additional stress on steering components and bearings.
Positive offset, tucking the wheels inward, does the opposite. It narrows the track, which can make the car more responsive and twitchy in corners, but it also increases the risk of rolling over. It also brings the wheels closer to the suspension components, meaning you have to be much more careful about choosing tires that won’t rub against the control arms or steering links at full lock.
Choosing the right offset is a balancing act between form and function. You might be chasing a particular look, wanting those deep-dish wheels to fill out the body arches perfectly. Or you might be chasing traction, using negative offset to widen the stance on a track that feels tippy. It is a simple measurement, just a few millimeters one way or the other, but it completely transforms the personality of the car the moment it hits the pavement.