What Is A Car Wheel Inch-Down? With Merit & Demerit

180 Automotive is reader-supported. This post contains affiliate links. As an Amazon Associate I earn from qualifying purchases.

Many people consider inch-downs to reduce the cost of purchasing tires with wheels or to improve ride comfort. Some people are particularly interested in inch-down when changing to studless tires.

Let’s take a look at the advantages and disadvantages of inching up a car’s wheels are, and what to look out for when inching down wheels.

What Is A Car Wheel Inch-Down?

Inch-down of a car wheel is also known as “size reduction” and refers to lowering the wheel size of the tire. The purpose of inching down is to reduce the price of tires when purchasing tires and to improve ride comfort.

For this reason, people who use studless tires during snowy seasons often use them in order to drive on snow-covered roads economically and safely. In addition, it is also easier to drive on rough roads such as ruts that form on snow-covered roads.

Merit and Demerit Of Inching Down Wheels

What are the advantages and disadvantages of inching down the wheels of a car?


The advantage of inch-down wheels is that it is more economical than anything else. The price of tires becomes much cheaper even if only one size is different. Even if you only look at the price advantage, it is well worth it to inch down.

In addition, the flatness ratio increases with the inch-down tire, which also improves shock absorption. Compared to before the inch-down, it can be said that the ride quality improves in any situation, regardless of whether the road is paved or unpaved.

Taking the example of studless tires that have been inching down, ground pressure is increased and the weight of the car is concentrated on a single point, so the tire grooves have more power to scrape off the water, making the tires less slippery against sherbet-like snow and water.

It is also more economical since the damage caused by the impact of driving on hard snow or ice is reduced, leading to a longer life of the tire.


The disadvantage of reducing the size of the tire is that it looks less cool. The tire portion will be thicker, so the stylish appearance will be spoiled.

In addition, the higher flatness ratio makes the wheels heavier to steer and less maneuverable than before inch-down, and the cornering performance and gripping performance will be reduced.

Cautions When Inching Down Wheels

The most important point to keep in mind when you inch down a car is “do not change the outside diameter of the tire. If you change the outside diameter of the tire, the tire may interfere with the vehicle body or cause the speedometer to go out of alignment, which is not safe.

Also, changing the outside diameter of the tire may violate the law, so it is recommended that the outside diameter of the tire be reduced without changing it.

In addition, the minimum wheel size that can be lowered differs depending on the car model. It is recommended that you consult with your dealer or a tire specialist before proceeding with the inch-down procedure.