When you purchase your car, you may want to customize your vehicle to better fit your daily driving needs. It’s essential to realize that the vehicle you bought—assuming it’s new with no previous modifications—was built and calibrated a certain way. You must consider this if you plan on switching out your tires for bigger or smaller ones. Knowing how tire size affects speedometer accuracy will help you better understand what tires you should be looking for.

The Importance of Tire Size

Your vehicle was specially designed to register your speed based on the size of your wheel. It does this by determining the rotations that your wheel makes and calculates your speed from that. For instance, if you replace your tires with larger ones, the time it takes to make one rotation is longer (albeit not by much).

How It Affects Speed Readings

Because it takes longer to do one rotation, your speedometer will register at a slower speed than you’re actually going. This is because it still believes that you have the smaller tire on and is basing its calculations on that.

How To Maintain Accuracy

You need to consider your wheel’s overall diameter. If you can keep your new tires within the original diameter, your readings should be as accurate as before. If you choose to have a low-profile tire, then you’ll need to compensate by having it on a larger wheel.

Stay Within Acceptable Parameters

Because it would be nearly imperceptible, a size difference of less than five percent is acceptable. However, anything more than that threshold runs the risk of incorrect speeds. Though, if you want tires that are bigger in diameter than your originals, then you will need to have your vehicle recalibrated to the new diameter.

Have What You Need

Tire size affecting speedometer readings can cause significant problems for you on the road and result in dangerous driving conditions. Know what your car is designed to register and make the necessary recalibrations to get it as accurate as possible. If you find it difficult to balance your tire-to-wheel ratio properly, contact RNR Tires in Topeka, Kansas. With their professional automotive mechanics, they can help you determine what exactly you need to get your speedometer in working order.