Confused about wheel sizes? Learn how to read tire markings, understand plus-sizing, and pick the right fitment for your car.
Category: Wheel Guides · 5 min read
Walking into a wheel shop can feel overwhelming. Diameters, widths, offsets, bolt patterns — it's a lot to absorb when you just want your car to look good and drive right.
This guide breaks down everything you need to know about choosing the right wheel size. By the end, you'll understand exactly what fits your vehicle and why.
Your current tires tell you everything you need to start. Look for a sequence like this:
235/45R18
Here's what each number means:
"Plus-sizing" means going up in wheel diameter while keeping the overall tire height similar. For example:
Plus-sizing gives you a more aggressive look and better handling response. The trade-off is a firmer ride and more expensive tires.
Critical rule: The overall diameter should stay within 3% of stock. Otherwise, your speedometer, odometer, and gearing will be off.
Offset determines how far your wheels stick out or tuck in. It's measured in millimeters:
Most factory wheels have high positive offsets. Aftermarket wheels often run lower offsets for a wider stance — but go too far and you'll rub fenders or suspension components.
Your wheels must match your vehicle's bolt pattern exactly. This is written as 5x114.3 (5 lug nuts, 114.3mm spacing) or 6x139.7 for many trucks.
No adapter can safely change this. If it doesn't match, the wheel doesn't fit.
Online fitment calculators are a good starting point. But they don't account for:
That's where we come in. Bring your vehicle to California Tires & Wheels, and we'll measure everything, test-fit options, and confirm what actually works.
Choosing the right wheel size comes down to three things: diameter, width, and offset. Match the bolt pattern, stay within 3% of stock diameter, and pick an offset that clears your brakes and fenders.
Want help finding the perfect setup? Stop by our San Jose location or give us a call. We'll walk you through every option.