What is the 3 tire rule?
The 3% tire rule is a widely used guideline in the automotive world. It says that the overall diameter of your new tires should not differ by more than 3% from the diameter of your original, factory-spec tires. The 3% rule states that when replacing tires, the new tire’s diameter should not differ from the original by more than 3%. This guideline helps maintain proper vehicle performance, safety system functionality, and speedometer accuracy.
Are 40 year old tires safe?
While there’s no hard-and-fast rule, and no federally mandated safety guidance on when a tire should be (ahem) retired, many carmakers and experts advise replacement between five and six years from the manufacturing date. Do tyres have an age limit? Tyres should be removed once they reach ten years of age, regardless of appearance, mileage or actual wear. However, most tyres will need replacing before they reach the ten year mark. That’s why it’s important to keep a close eye on the condition of your tyres.
What is the 7 7 rule for tires?
Some experts go one step further and refer to the 7-7 rule. This means fitting winter tyres when temperatures stay at or below 7°C for seven consecutive days, and removing them after seven days consistently above 7°C in spring. If you leave them on too long, your winter tires will degrade quickly. So, when is the right time to swap? The rule of thumb is 7-for-7: wait until there are seven consistent days at 7 degrees Celsius. The reverse is also true for transitioning to winter.