Curious about wheels? Read on to learn more about wheel terminology.

Wheel Size
The two components of a wheel's size are the wheel diameter and the wheel width. For example, a 17 x 8 wheel would have a 17" diameter as measured across the center, and an 8" width as measured from the front rim to the rear rim.

Bolt Circle
The bolt circle of a wheel is the diameter of the imaginary circle formed by the centers of the wheel's bolt mounting holes. For example, a bolt circle of "5x4.5/120" would indicate that the wheel has a 5-lug pattern with a 4.5" or 120 mm diameter. Consult your local Fountain Tire to ask about the bolt circle for your vehicle.

Offset
The offset of a wheel is the distance from the centerline of the wheel to the mounting surface where the wheel contacts the hub.

If a wheel has a zero offset, the mounting surface is inline with the centerline of the wheel.

If the offset of the wheel is positive, the mounting surface to the hub is in front of the centerline and towards the street side of the wheel. Many wheels designed for front wheel drive cars will have a positive offset.

If the wheel offset is negative, the mounting surface is behind the wheel centerline and towards the back side of the wheel. Many rear wheel drive vehicles will feature wheels with a negative offset.

 

 

The bolt circle of a wheel is the diameter of the imaginary circle formed by the centers of the wheel's bolt mounting holes. For example, a bolt circle of "5x4.5/120" would indicate that the wheel has a 5 lug pattern with a 4.5 inch or 120 mm diameter. Consult your local Fountain Tire to ask about the bolt circle for your vehicle.

 

Find a Store Near You

Search for Tires & Request a Quote

---

Careers