Correctly selected car tires ensure the safety and performance of the vehicle. If it is not possible to install tires recommended by the automaker, it is necessary to choose an interchangeable tire size, taking into account several parameters.
Instructions
Step 1
Decipher the standard size of car tires. For example, in the designation 175 / 65R14, the first 3 digits indicate the width of the tire in millimeters, 4 and 5 digits - the tire profile (in% of the width). The R is the radial tire designation and the last 2 digits indicate the rim diameter in inches.
Step 2
Choose tires that are slightly different in physical size from the "native" ones. Deviation in diameter up to 5% and in width up to 20% is considered acceptable. Compare the total diameter of the wheel fitted to the vehicle with the new size. Total volume = disc diameter x 25.4 mm. + (tire width x (tire profile / 100) x 2). For example, if you want to change the size 175 / 65R14 to 195 / 50R15, substitute the corresponding parameters from these designations into this formula. Having received as a result of calculations two values (583, 1 mm. And 576 mm.), Find their difference and the percentage that it is from the original volume. In this example, the difference is 7, 1 mm. is 1, 2% of the original volume of 583, 1 mm. and is a valid value. Therefore, you can safely change the size of your car tires.
Step 3
Compare the section height and tire width. For example, you want to change the size 175 / 65R14 to 185 / 60R14. Multiply the tire width by the profile (175 mm x 0.65 and 185 mm x 0.66). The difference between the obtained values (113, 75 mm. - 110 mm. = 2, 75 mm.) Is 2.4% of the initial profile height (113, 75 mm.). The difference in tire width (185 mm -175 mm) is 10 mm. and 5.7% of the width of 175 mm. Thus, it can be concluded that the sizes 175 / 65R14 and 185 / 60R14 are interchangeable.
