Themain difference between tire sizes 215/45r17 and 215/50r17 is the sidewall height. The 215/50r17 has a sidewall height of 4.23 inches (107.5mm), which is 11.1% higher than the 21545-R17 tires are 0.15 inches (3.9 mm) smaller in diameter than 215/40-R18 tires and the speedometer difference is 0.6%. 20555-R16 tires are 0.26 inches (6.6 mm) larger in diameter than 215/45-R17 tires and the speedometer difference is 1.0%. 21545-R17 tires are 1 inch (25.4 mm) smaller in diameter than 215/45-R18 tires and the speedometer difference is 3.9%. 23545-R17 tires are 0.71 inches (18 mm) larger in diameter than 215/45-R17 tires and the speedometer difference is 2.8%. Helpful9 - tyre reviewed on October 8, 2023. Given 88% while driving a Mercedes Benz E350 CDI Coupé 231hp (225/50 R17) on mostly motorways for 500 average miles. I went from 235/45 R17 Continental WinterContact TS 850 P to 225/50 R17 Intensa UHP2. The Sava is comfortable, silent and the grip (dry) is amazing. 22560-R17 tires are 2.66 inches (67.5 mm) larger in diameter than 225/45-R17 tires and the speedometer difference is 9.6%. UHP& Touring HP Allseason Enjoy a smooth ride, all year long. The upgraded Nexen Nfera Supreme combines the look of a performance tire with the comfortable, quiet ride of a passenger tire. Branded with the M+S symbol, this tire provides year-round traction, even in light snow. And with its long tread life, the Nexen Nfera Supreme can handle some RideComfort. Tire Description. Pole position speed to chase your competitive spirit. The Bridgestone Potenza RE-71RS delivers improved corner grip and blistering lap times to help you capture success every time you hit the track.*. Plus, with improved wear performance the Bridgestone Potenza RE-71RS helps you enjoy more exhilarating weekends 21545/17 vs. 225/45/17 vs. 215/50/17. I see the recommended upgrade from the stock 205/55/16 tires on my EX sedan is 215/45/17 according to this forum and TireRack. However, Discount Tire recommends a +1 size of 215/50/17. I like the fact the 215/50/17 and 225/45/17 have a slightly larger diameter than stock, and also still have a decent 8ZRk.