The numbers you provided refer to the tire size, which is a popular "wide profile" choice for trucks and SUVs. Tire Size Breakdown
Offers an "aggressive" look for larger vehicles. 90 531 305 50 20
You can find this size in several styles at retailers like Discount Tire or Custom Offsets : 305/50/20 Performance Tires for sale - eBay The numbers you provided refer to the tire
: Section width in millimeters (distance from sidewall to sidewall). 50 : Aspect ratio (the sidewall height is 50% of the width). 20 : Diameter of the wheel rim in inches. Physical Dimensions A 305/50R20 tire typically has the following measurements: Total Height: Approximately 32.0 inches . Width: Approximately 12.0 inches . Sidewall Height: Roughly 6.0 inches . Performance & Style 50 : Aspect ratio (the sidewall height is 50% of the width)
Provides a broader grip on the road, improving responsiveness.