You need new tires. You check the sidewall and see: 225/45R17 94W. That's a lot of numbers and letters. Here's what every single part means — and why it matters when you're buying tires.
Breaking Down 225/45R17 94W
225 — Section Width
The width of the tire from sidewall to sidewall in millimeters when mounted and inflated. A 225 tire is 225mm (about 8.9 inches) wide. Wider tires generally have more contact patch and better dry traction; narrower tires can be better in wet conditions and get better fuel economy.
45 — Aspect Ratio
The height of the sidewall as a percentage of the width. A 45-series tire has a sidewall height equal to 45% of 225mm = about 101mm (4 inches). Lower numbers mean a shorter sidewall (low-profile). Lower profiles look sportier but ride harsher and are more vulnerable to pothole damage.
R — Radial Construction
Virtually all modern passenger tires are radial construction — the internal cords run perpendicular to the direction of travel. "R" just confirms this. You'll rarely see anything else on a modern vehicle.
17 — Rim Diameter
The diameter of the wheel in inches that this tire fits. A tire marked 17 only fits on a 17-inch wheel. This is non-negotiable — a 17-inch tire will not mount on an 18-inch wheel.
94 — Load Index
94 = 1,477 lbs maximum load per tire. The load index scale goes from 70 (739 lbs) to 126 (3,748 lbs). For trucks and vehicles that carry loads or tow, matching or exceeding the OEM load index is critical.
W — Speed Rating
W = maximum sustained speed of 168 mph. Common ratings you'll see: S (112 mph), T (118 mph), H (130 mph), V (149 mph), W (168 mph), Y (186 mph). Always match or exceed your OEM speed rating.
Where to Find Your Correct Tire Size
The most reliable source is the driver's door jamb sticker — open the driver's door and look at the edge of the door frame or the door itself. The sticker will show your factory tire size and the correct inflation pressure. This is what your car was engineered to run.
Your existing tires may show the same size, or may have been changed previously. If they're a different size from the door sticker, ask us — we'll tell you whether the current size is appropriate or whether you should return to factory spec.
Understanding Plus-Sizing
Plus-sizing means fitting larger diameter wheels with lower-profile tires to maintain the same overall tire diameter. Example:
- Factory: 225/55R17 (17-inch wheel, 55-series profile)
- Plus-one: 225/50R18 (18-inch wheel, 50-series profile)
- Plus-two: 225/45R19 (19-inch wheel, 45-series profile)
The goal: the overall diameter stays nearly the same (keeping the speedometer accurate) while the wheel gets larger. The tradeoff is a stiffer, harsher ride and increased rim vulnerability to pothole damage — a real consideration on Long Beach roads.
Bring your vehicle in and we'll size it up. If you want to plus-size, go to a different brand, or just replace with the same spec, we'll pull the right tire for your vehicle and show you options at different price points before you decide.
Frequently Asked Questions
Where do I find my correct tire size?
Three places: the driver's door jamb sticker (most reliable — this is the factory spec for your vehicle), the owner's manual, or the sidewall of your existing tires. Note that the door sticker shows the factory size, while your existing tires may be a different size if they were changed previously.
Can I put a different size tire on my car?
Yes, within limits. Changing tire size affects speedometer accuracy, clearance, handling, and load rating. Minor changes — like going from a 45 to a 50 series profile — are generally fine. Significant changes should be calculated carefully. We can advise on acceptable size changes for your vehicle.
What is plus-sizing (plus-one, plus-two)?
Plus-sizing means going to a larger diameter rim while using a lower-profile tire to maintain the same overall diameter. A plus-one goes up one rim size (e.g., 17" to 18"). The advantage: larger wheels look better and can improve handling with stiffer sidewalls. The tradeoff: harsher ride and more vulnerability to pothole damage.
What does the speed rating mean on a tire?
The speed rating (S, T, H, V, W, Y, Z) indicates the maximum sustained speed the tire is certified for under load. H = 130 mph, V = 149 mph, W = 168 mph. Most street vehicles use H or V-rated tires. Always replace with a tire that meets or exceeds your vehicle's OEM speed rating.
What is the load index on a tire?
The load index is a number that corresponds to the maximum weight each tire can safely carry. A load index of 94 = 1477 lbs per tire. Always replace with a tire at or above your OEM load index, especially on trucks and SUVs where load capacity matters.
Have this problem right now? Ochoa's Tire Service is open 7 days a week — no appointment needed for most services.