At what millimeter of wear should motor vehicle tires be replaced?
3 Answers
Motor vehicle tires need to be replaced when the tread pattern depth wears below 1.6 millimeters. Here are the reasons for tire wear: 1. Excessive wear on both sides: The main causes are insufficient inflation or long-term overload driving. When the inflation is low or the load is heavy, the contact area between the tire and the ground increases, causing both sides of the tire to come into contact with the ground and resulting in premature wear. 2. Excessive wear on one side: The main cause is misalignment of the front wheels. When the camber angle of the front wheels is too large, the outer edge of the tire experiences premature wear. If the camber angle is too small or nonexistent, the inner edge of the tire wears prematurely. 3. Sawtooth-shaped wear on the tread: The main causes are improper front wheel alignment adjustment, abnormal front suspension system positioning, or loose ball joints, which cause normally rolling wheels to slip or continuously change their positioning during driving, leading to sawtooth-shaped tire wear.
Worn-out tires are extremely dangerous. After driving for so many years, I'm most afraid of encountering shallow treads. The standard is to replace them when they wear down to 1.6 mm, because at this depth, braking distance can double or even triple in rainy conditions, increasing the risk of skidding or losing control. I usually use a one-yuan coin to check—insert it into the tread, and if the entire head of the coin is visible, the depth is insufficient. Remember to inspect regularly—don't wait until an accident happens to regret it. Tire lifespan depends on driving habits; city driving causes slower wear, but check at least two or three times a year. Using tires below 1.6 mm increases the risk of a blowout, especially on highways or curves. Spending a bit more on new tires is far better than paying for car repairs or medical bills later.
I once towed an old tire with tread depth down to about 1.5mm. During a heavy rainstorm on the highway, the car felt extremely floaty—fortunately, nothing bad happened. Since then, I've made it a habit to check the tread depth every time I wash the car, using a simple depth gauge placed into the tread grooves. Generally, anything below 1.6mm is the replacement point. After installing new tires, the grip improved significantly, and steering felt much more stable. For daily driving, especially on rough roads, wear tends to accelerate faster. I recommend checking every 5,000 km. Don’t skip replacement to save money—worn tires increase fuel consumption, making it costlier in the long run. Safety should always come first.
