Quality evaluation must focus on tread depth, which should ideally be above 4mm to 6mm for premium resale value. Inspect for sidewall integrity, ensuring there are no bulges, cracks, or 'dry rot' caused by UV exposure. It is critical to verify the DOT (Department of Transportation) code to determine the tyre's age; tyres older than 5-6 years are generally considered high-risk regardless of tread wear. Additionally, ensure the tyres have undergone pressure testing to detect micro-leaks that are invisible to the naked eye.