What is my stock tire size?
I can't determine your exact stock tire size without specifics about your vehicle (make, model, year, and trim). Here’s how you can find the OE size accurately and what the numbers mean.
Where to find your stock tire size
Use These reliable sources on or for your vehicle to confirm the original equipment size. Each source typically lists the same size, which helps ensure you replace tires correctly.
- Door jamb placard: A sticker on the driver’s door jamb (or in the door frame) usually shows the recommended tire size and inflation pressures.
- Owner’s manual: The Tires or Specifications section lists the OE tire size for standard equipment and may note alternative sizes for different trims.
- VIN-based records or dealer/brand website: A dealership or official manufacturer database can pull the exact OE size by VIN.
- Spare tire label: Some vehicles note the appropriate spare size, which can reflect the standard tire size in case of a full-size spare.
- Build sheet or window sticker (for new cars): The original specifications printed at purchase often include the OE tire size.
Keep in mind that if you’ve swapped wheels or tires in the past, or if you’re looking at a different trim or model year, the current tires may differ from the original OE size. The placard is typically the most reliable single reference.
Door jamb placard
The door jamb placard is the quickest, most reliable source for the OE tire size. Look for a line that reads something like "TIRE SIZE" followed by a format such as P215/65R15 or 225/50R17. It may also list the recommended cold tire pressures for front and rear tires.
Owner’s manual
In the manual, search the Tires or Specifications sections for the factory tire size. This can be especially helpful if the placard is missing or damaged.
VIN-based records
A dealer or online VIN lookup can confirm the OE tire size tied to your specific vehicle configuration. This is useful if you no longer have access to the original paperwork.
How to read the tire size code
Vehicle tires display a size code on the sidewall that encodes width, aspect ratio, construction, and wheel diameter. Here is how to interpret a typical code:
- P or LT indicates the tire type: P = passenger car; LT = light truck.
- Width (in millimeters) is the first number (e.g., 215).
- Aspect ratio is the second number after the slash (e.g., 65) and represents the sidewall height as a percentage of the width.
- R means radial construction; the next number is the wheel diameter in inches (e.g., 15).
- Additional numbers/letters include load index and speed rating (e.g., 95H) which relate to load-carrying capacity and maximum sustained speed.
Example interpretation: P215/65R15 95H means a passenger-car tire, 215 mm wide, 65% aspect ratio, radial construction, for a 15-inch wheel, with a load index of 95 and speed rating H.
Example interpretation
For a tire labeled P225/60R17 97T: 225 mm width, 60% sidewall, radial construction, 17-inch wheel, load index 97, speed rating T. This helps ensure you match the OE size when shopping for replacements.
Why it matters to know your stock tire size
Knowing the OE tire size helps you maintain intended performance, handling, ride comfort, and safety. Using tires with a different diameter or width can alter speedometer accuracy, ABS/traction control behavior, gearing feel, and clearance in the wheel wells.
If you plan to change sizes, you should aim to keep the overall diameter close to the original. Large deviations can require recalibration, suspension or brake compatibility checks, and potential clearance considerations.
Guidelines if you’re considering a size change
Before changing tire sizes, consider these guidelines to minimize issues:
- Keep the overall tire diameter within about 3% of OE to preserve speedometer accuracy and drivetrain dynamics.
- Prefer matching wheel diameters when changing tire width or aspect ratio to reduce the risk of clearance problems.
- Check load index and speed rating to ensure the new tires can handle the vehicle’s weight and performance requirements.
- Ensure adequate clearance in the wheel wells and with any suspension components or brakes; consult a tire professional if unsure.
Always verify any size changes with a tire shop or your vehicle’s manufacturer to avoid safety or warranty issues.
Summary
Your stock tire size is the original equipment size specified by the manufacturer for your exact vehicle configuration. To locate it, check the door jamb placard, the owner's manual, VIN/build records, or the spare label. Learn to read the sidewall code to identify width, aspect ratio, and wheel diameter, and be cautious about changing sizes, since diameter, clearance, and system calibrations can be affected. If in doubt, consult a professional to ensure safe and optimal performance.
How do I know my stock tire size?
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.
What does 4.80 4.00 mean?
The numbers 4.80/4.00-8 read like this: 4.80" is the tire width, 4.00" is the tire section height (from the inside of the donut hole to the outside) and the 8" is the wheel diameter. Finally, the numbers 4.80-8 read like this: 4.80" is the tire width and "8 is the wheel diameter.
Is a 275 tire the same as a 33?
No, a "275 tire" is not the same as a "33-inch tire" because the numbers represent different measurements in a tire's size. However, a specific metric size, such as a 275/60R20, can be nearly equivalent to a 33-inch diameter tire. The term "33" is a common, non-metric measurement for a tire's approximate overall diameter.
Tire size explained
- Metric size (e.g., 275/60R20): This is a precise measurement with three parts:
- 275: The width of the tire in millimeters.
- 60: The aspect ratio, which is the height of the sidewall as a percentage of the width (60% of 275mm).
- R20: The radial construction and the diameter of the wheel in inches.
- Non-metric size (e.g., 33x12.5R20): This is a common, more direct way to refer to a tire's approximate overall diameter:
- 33: The approximate total height of the tire in inches.
- 12.5: The width of the tire in inches.
- R20: The radial construction and the diameter of the wheel in inches.
When they are similar
- A 275/60R20 tire is a close equivalent to a 33-inch tire, with a total diameter of approximately 33 inches.
- Other metric sizes, like a 285/75R16, also result in a diameter close to 33 inches.
Why it matters
- Compatibility: Always check the exact metric size of a tire to ensure it will fit your vehicle and is compatible with your suspension and wheel size.
- Speedometer accuracy: Changing your tire diameter significantly can cause your speedometer to be inaccurate. For example, larger tires will make you appear to be driving faster than you actually are.
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.
