Better Fuel Economy Factory Ratios Increased Power. vs 225/50-17 vs 225/45-17 vs 275/40-17. 235/45-R17 tires are 0.35 inches (9 mm) smaller in diameter than 245/45-R17 tires and the speedometer difference is 1.4%. .

225 50 r17 vs 245 45r17