The 275/45R21 tire is a premium SUV and crossover tire size designed for a balance of comfort, stability, and performance. The “275” shows the width in millimeters, “45” is the aspect ratio (sidewall height is 45% of width), and “R21” means it fits a 21-inch rim.

Compared to lower-profile options like 275/40R21 or 275/35R21, this tire has a taller sidewall, which improves ride comfort and shock absorption while still maintaining strong highway stability.

It is commonly used in luxury SUVs such as BMW X5/X7, Mercedes GLE, Audi Q7, Range Rover Sport, Jeep Grand Cherokee L, and similar premium vehicles.

In terms of performance, the 275/45R21 offers:

• Strong road grip on dry and wet surfaces
• Better comfort than low-profile 21-inch tires
• Stable high-speed highway driving
• Good load-carrying capacity for SUVs

However, because of the 21-inch rim size, it can still be expensive and slightly less fuel-efficient than smaller wheel setups. Also, like all low-profile SUV tires, it still requires careful driving on rough roads to avoid sidewall damage.

Key Highlights

• Tire Size: 275/45R21
• Type: Premium SUV / Touring Performance
• Best for: Comfort + highway stability
• Strengths: Smooth ride, good grip, durability
• Weakness: Expensive, moderate fuel efficiency impact
• Rim size: 21 inch