What is wheel offset, and why is proper offset important for spare tires?

Wheel offset is a design feature that determines how the vehicle weight is carried by the wheels and tires. Improper offset on a spare tire may put added stress on the vehicle drivetrain, wheel bearings and other suspension components.

If you look at a car from the rear or front, imagine shifting the tires inward toward the car's center or outward away from it. Essentially, you now understand wheel offset and its implications. When a carmaker designs a vehicle, ensuring that all four wheels support the car's weight evenly will determine the wheels' offset measurement. It's important to note that the correct offset measurement for a specific car will vary based on the width of the wheels. 

Wheel offset is usually presented as positive or negative numbers in millimeters (MM). This measurement is determined by assessing the position of the lateral centerline of the wheel in relation to where the wheel connects to the vehicle's hub. The aim is for the tire tread to meet the road in a position beneath the car that provides adequate load-carrying support. Therefore, a wider wheel and tire will have a different offset measurement compared to a narrower wheel and tire, yet both can achieve proper load-carrying balance.  

Modern Spare takes offset very seriously, designing our wheels with this in mind. In fact, when creating a narrow, space-saving wheel, we could have significantly simplified the design process and avoided major challenges by compromising on the correct offset.  
While our customers may not understand what the proper offset is for a spare tire or recognize its importance, this essential measurement justifies the additional engineering complexity and effort.  
A well-designed spare tire is critical, and proper offset demonstrates our high standards.