245/40R17 tire size breakdown:
245 = Tire width is 245 mm
40 = Aspect ratio, meaning the sidewall height is 40% of 245 mm = 98 mm
R = Radial tire construction
17 = Fits a 17-inch rim
Approximate Dimensions
Sidewall height: 98 mm
Overall tire diameter: 628 mm (24.7 inches)
Characteristics
Wide contact patch for enhanced grip
Responsive handling and cornering performance
Lower-profile design gives a sporty appearance
Suitable for performance sedans, sports cars, and modified vehicles
Common Vehicle Applications
This size is commonly used on models such as:
BMW 3 Series
Nissan 350Z
Subaru WRX STI
Mitsubishi Lancer Evolution
Compared with a 245/45R17, the 245/40R17 has a lower sidewall, giving sharper steering response but a firmer ride.