How to Determine the Correct Tire Size for Your Vehicle

When it comes time to replace your vehicle's tires, the first step is determining the correct tire size. This information can often be found directly on the tire placard inside the driver's door or in the owner's manual. Incorrect tire size can affect your vehicle's performance, safety, and fuel efficiency. Here, we'll guide you through the process of finding and using this crucial information.

Locating the Proper Tire Size

The correct tire size for your vehicle is typically listed on the tire placard inside the driver's side door or in the owner's manual. However, this is not a hard and fast rule. The tire placard is the more reliable source of information, as it provides precise details about the proper tire size, inflation specifications, and sometimes the load and speed ratings.

Read the Information on the Tire Sidewall

The size and important ratings of the tires are clearly visible on the sidewall. This information is usually in a format like: 205/65R16 95H. Here's what each part of this code stands for:

205: This is the width of the tire in millimeters. 65: This is the aspect ratio, which is the height of the tire sidewall as a percentage of the tire's width. R: This denotes that the tire uses a radial construction. 16: This is the diameter of the wheel the tire is intended to fit in inches. 95: This is the load index, which corresponds to the maximum load the tire can safely carry. H: This is the speed rating, which indicates the maximum speed the tire can safely be driven at.

Using the Doorjamb Sticker

The easiest and most reliable way to find the correct tire size is to look at the sticker on the driver's side doorjamb. This sticker provides the correct tire size and inflation specifications. Remember, the car's tire size is molded into the rubber of the sidewall, but this method is not foolproof, as the tire placard inside the door should always be your primary reference source.

Online and Shop Resources

If you are unsure about the tire size or need more detailed information, you can use online reference tables or visit your tire shop. These resources can provide additional details such as maximum inflation pressure and load capacity.

Importance of Correct Tire Size

For all cars and trucks, the size is clearly molded into the exterior tire wall. For example, 235/65/R17. This is the number you need to know when replacing tires. Correct tire size ensures that your vehicle maintains its optimal performance, safety, and fuel efficiency. Mixing tire sizes or types can lead to issues such as misalignment, uneven wear, and reduced handling.

If you have any doubts or questions about tire specifications, especially if you are a novice or have a particular type of vehicle like a wheelchair, it is best to consult a professional tire technician. Leaving tire changes or replacements to a professional ensures that the proper size, types, and specifications are used, safeguarding the safety and performance of your vehicle.

Remember, the tire placard inside the driver's door is your primary reference. Do not rely solely on the tire sidewall markings for critical tire size information. Always cross-reference with the doorjamb sticker or the owner's manual for the most accurate and reliable data.