Which Tire Sizes Are Interchangeable? A Complete Guide.

Last updated on January 11th, 2024 at 05:35 pm

Tires, just like cars, motorbikes, and other vehicles are different in shape, size, and quality, and just like other parts of the vehicle can not fit with any other kind of vehicle similarly different tire sizes can not fit with every other car. 

Keeping a closer look at tires is very important because once you get the wrong-sized tires, you will stuck with them for a longer period. 

Sometimes, drivers change the sizes of tires from the front to the rear axle, and many inexperienced drivers cause many issues just because they have no idea about which sizes are interchangeable and equivalent to their OEM tires. 

It is never necessary to put different-sized tires on both axles of the vehicles, but if someone wants to do that, they should do it properly to avoid any danger while driving. 

Interchanging tire sizes does not mean any tire size you find attractive; you put it on your vehicle. On the contrary, there are very few options when going for interchanging the sizes of tires, 

Some sports cars and classic cars usually modify the sizes of tires, so there might not be a big change in performance; however, drivers do this for looks, speed, and balance of the car.

So if you want to change the tire sizes from the OEM size tires, then read this article through the end to learn how to do it properly and also correct your mistakes if you have already done that, 

Introduction

Different tire sizes

Although there are thousands of tire sizes available for every tire, there are only two sizing metrics for tires. One is called metric sizes, which are written 205/45R16 and LT215/45ZR16 in these formats. 

The other tire sizing figure is called flotation size, which is written 33×13.5R16 in this form. The difference in size does not make them different tires, just they are more often made for light trucks and commercial vehicles. Compared to metric size diameters, in this, sidewall diameter is written in inches, and instead of aspect ratio, the tire total diameter is also given and other things are just as same as metic size tires. 

How to read tire sizes

The first number on metric tire sizes are total sidewall width in millimetres, the second number is called aspect ratio which is the percentage of a sidewall height compared to the width of a tie sidewall. After that, an alphabet represents built, and finally, the wheel diameter in inches, which you can not go wrong because it won’t fit if you buy 18-inch tires to fit on 16-inch rims. 

In flotation sizes, the first number represents the total diameter of the tire in inches, and then a sidewall width is given in inches and not in millimetres of metric sizes. Then built and rim diameters in inches. 

Which tire sizes are equivalent

Metric vs. flotation sizes

Figures in these tires are different, so without making any calculations it is not possible to find the correct sizes. So if you have tires with both matric and flotation sizes in different axles, the best way to compare sizes is to go through tire size calculators which will give you an exact comparison of both of these tires. 

Different metrics tire sizes

Different tire sizes are only possible if you install the same tires on one side of the axle; it is not possible if all tires on each axle are different in size, whether you can change both front axle tire sizes or rear axle tire sizes. 

It is recommended that whatever size you choose, it should not go above the difference of 3 inches diameters because a size difference of more than 3 will cause disbalance while driving and also wear off faster than smaller tires. 

Different rear and front tire

The purpose of modifying tire sizes is mostly due to the looks and performance of a vehicle; as we mentioned, if you want to do it, just don’t go beyond the 3-diameter difference, and all will be fine. Some classic cars have noticeable differences between front and rear axles, which might not work with your car unless it is authorized by the car manufacturers. 

Vehicle perspective

Front-wheel drive

If you are a driver of a front-wheel vehicle, then you should modify the front wheels, as they are in contact with the torque. The wider tire should be fitted on the front wheel and smaller on the rear axles. By doing this, you will achieve faster, more responsive, and stable ride. 

Rear wheel drive

Similarly, if you drive rear-wheel cars, the wider and bigger tire should be installed on the rear axles, the performance and stability will improve with weight-carrying ability. However, the tread will wear off far quicker on the rear tire, due to the more contact and more rolling wider tires. Also, rotation is not possible among different tire sizes; you have to replace tires in different time periods as rear wheel tires will get bald far earlier than front axle tires. 

Four wheel drive

For font wheel divers, look at your car manual, or don’t try changing tire sizes, if you want wider tires, then install them in all axles. It is always a safer, more durable option to drive with same-size tires, the modification is for those who like to do acing on tracks and other fast-paced activities with their vehicle. 

Impacts of different wheel size tires

Rolling resistance

Change tire sizes increase low Rolling as one side of the car requires more force to move even without different sizes, big tires require more force to move and roll at a lower pace compared to smaller and original equipment sizes. So if you want more affordable rides, it is better you go with the recommended tires or with smaller tires. 

Speed, traction, grip

The disbalance among cars causes low traction and grip when you drive with different-sized tires. With that, the speed of the car might improve, but the wearability of the tire also increases. There are many other causes that could happen, like imbalance rides, more torque, more fuel consumption, and many more. 

Treadwear

Tire rotation is very important, especially if you have 2WD, as it confines the driver to rotate the tire if you have different tires on both axles, the tread of a tire wears off earlier than the other side of the tire tread. For a time when the tires are new, the drive might feel better, however as the time goes on, the stability, comfort, reliability, and safety all will be disturbed due to uneven worn tires.

Conclusion

The concept of different tire sizes on axles might excite you, but it is not always the best decision. The performance might improve for a shorter period but after a few miles, there will be uncountable problems if you do not do it correctly. That is it is important whenever you are going for different sizes on axles, you don’t go above and beyond 3 inches in diameter. Unless there is a proper reason, don’t change the tire size and drive with the original equipment tire sizes.