What size tires does my vehicle use?
The tire size your vehicle uses is shown on the tire sidewall and on the door‑jamb placard, and you should replace tires with the same size (or a manufacturer-approved equivalent) to maintain performance and safety. A typical tire size code looks like P215/65R15, which encodes width, profile, and wheel diameter.
Where to find your tire size
Most drivers will find the official size in a few reliable places. The following sources are the quickest and most authoritative for your vehicle’s OEM specification.
- Tire sidewall markings: Each tire is labeled with a size code such as P215/65R15, often repeated on all four tires.
- Door‑jamb placard: A sticker on the driver’s door post (or fuel filler door on some models) lists the recommended size for front and rear tires.
- Owner’s manual: The manual specifies the factory-recommended size and any approved alternatives.
- Spare tire or kit: The temporary spare (donut) or space‑saver may use a different size; use caution if you need to drive on it for an extended period.
- Manufacturer or dealer resources: If you’re unsure, your dealership or the manufacturer’s online VIN/assembly database can confirm the exact spec for your exact vehicle.
In practice, the door‑jamb placard and the sidewall markings are the quickest ways to confirm the correct size. Always cross‑check with the manual or dealer if you’re unsure before buying replacements.
How to read tire size codes
Understanding what the letters and numbers mean helps you compare options and ensure compatibility with your vehicle’s systems.
- Prefix letters (P, LT, or T): P = standard passenger car, LT = light truck, T = temporary spare.
- Width: The first number (e.g., 215) is the tire width in millimeters from sidewall to sidewall.
- Aspect ratio: The second number (e.g., 65) is the height of the sidewall as a percentage of the width.
- Construction: The letter after the slash (R) indicates construction type; R = radial, D = diagonal.
- Wheel diameter: The final number (e.g., 15) is the diameter of the wheel in inches that the tire fits.
- Load index and speed rating: The numbers/letter after the size (e.g., 95H) indicate maximum load capacity and the maximum safe speed.
- Metric vs. imperial: The same concepts apply to both; some sizes use metric notation (e.g., 205/60R16) rather than P‑type prefixes.
Knowing these elements helps you compare OEM sizes with alternatives and confirms you’re selecting tires that fit your wheels and support your vehicle’s performance expectations.
Replacing tires: what to keep in mind
When you buy replacements, there are practical rules to ensure safety, handling, and regulatory compliance remain intact.
- Keep overall diameter close to OEM: Aim for within about 3% of the factory tire diameter to avoid speedometer errors and traction system mismatches. Significant deviations can affect ABS, traction control, and ride quality.
- Check speed and load ratings: The replacement tires should meet or exceed the vehicle’s required speed rating and load index.
- AWD/4WD considerations: If your vehicle uses all‑wheel drive, avoid mixing sizes across axles; ideally, install the same size on all four corners or consult the manufacturer for approved variants.
- Seasonal tires and sizes: If you run winter tires or seasonal swaps, try to maintain the same size on all wheels or follow the manufacturer’s guidance to prevent drivetain stress and handling changes.
- Wheel compatibility: Verify the chosen tire’s width and aspect ratio fit within your wheel arches and do not rub at full lock or during suspension travel.
Following these guidelines helps preserve braking performance, steering feel, and the longevity of safety systems that rely on accurate tire dimensions.
Summary
To know your vehicle’s tire size, check the sidewall code and the door‑jamb placard, then verify with the owner’s manual or dealer if needed. Decode the size to understand width, profile, construction, wheel diameter, load index, and speed rating. When replacing tires, match overall diameter, meet or exceed the required load and speed ratings, and consider AWD implications and seasonal tire needs. By sticking to the OEM size or an approved equivalent, you keep handling, safety, and instrument readings accurate.
How do I find out my tire size?
Every tyre carries a code on the sidewall that tells you its width, profile, rim diameter, load capacity and speed rating. Understanding these details is important when choosing replacements, as fitting the wrong size can affect handling and safety, as well as fuel efficiency.
What is the 7 7 rule for tires?
If you leave them on too late, your winter tires will degrade quickly. So, when is the right time to swap? The rule of thumb is 7-for-7: wait until there are seven consistent days at 7 degrees Celsius. The reverse is also true for transitioning to winter.
How to find out what size tires your car has?
Find the information in your vehicle owner's manual in the glove compartment or on the tire information sticker on your driver's side door. Usually those elements contain all the information related to your tire size and specifications as well as the appropriate tire pressure.
Can I look up tire size by VIN number?
No, a VIN number does not typically contain tire size information directly, but you can use a VIN lookup tool on many automotive websites to find the original equipment (OE) tire size for your vehicle's specific make, model, and trim. Other reliable methods include checking the sticker on your driver's side door jamb, your owner's manual, or the sidewall of your current tires.
Ways to find your tire size
- Use a VIN lookup tool: Many websites, such as AutoZone, CARFAX, and Discount Tire, have VIN decoders that will provide your vehicle's specific trim and tire size.
- Check the driver's side door jamb: This is the most common place to find a sticker with the original equipment tire size and recommended pressure.
- Read your owner's manual: Your vehicle's manual will contain the recommended tire size for your specific model and trim.
- Look at your current tires: The size is printed on the sidewall of your current tires, but be aware this may not be the original size if the tires have been changed.
- Search online for your vehicle's make, model, and trim: This will help you find the correct specifications, as different trims of the same car can have different tire sizes.
