In the tire comparison table above, you can see a detailed calculation of the size difference between 225/55 R18 and 225/50 R18 tire. The calculation results are presented in the form of visual infographics, on which tire with size 225/55 R18 is on top, and tire with size 225/50 R18 below. Both in the table and in the graph, the tires are In the tire comparison table above, you can see a detailed calculation of the size difference between 225/40 R18 and 255/35 R18 tire. The calculation results are presented in the form of visual infographics, on which tire with size 225/40 R18 is on top, and tire with size 255/35 R18 below. Both in the table and in the graph, the tires are Mar 28, 2023 · 1st: 2021 Auto Zeitung Summer UHP Tyre Test (225/40 R18) 1st: 2021 Tyre Reviews UHP Summer Tyre Test (225/40 R18) 2nd: 2021 Motor Summer Tyre Test (225/55 R17) 3rd: 2021 Sport Auto UHP Summer Tyre Test (275/35 R19) 5th: 2021 Auto Express Summer Tyre Test (225/45 R17) 6th: 2021 Camper Van / SUV Tyre Test (235/55 R17) 255/40-R18 tires are 1.06 inches (26.9 mm) larger in diameter than 225/45-R17 tires and the speedometer difference is 4.1% The first number 225 is the tire width in millimeters. The 2nd number 40 is used to calculate the sidewall height or "aspect ratio", by percentage. So, the sidewall height of a 225/40 R 18 tire is 60% of 225 = 192. The 3rd number 18 (generally preceded by an "R") is Rim Diameter in inches. 3rd: 2018 Auto Review 225/45 R17 Tyre Test (225/45 R17) 5th: 2018 ADAC Summer Tyre Test - 205/55 R16 (205/55 R16) 5th: 2018 AZ Summer AND All Season Tyre Test (225/45 R17) 7th: 2018 Gute Fahrt Summer Tyre Test (205/55 R16) 2017 Tyre Tests; 2nd: 2017 Auto Bild Summer Tyre Shootout (225/50 R17) 4th: 2017 ACE SUV Summer Tyre Test (215/60 R17) 225/50-R17 tires are 1 inch (25.4 mm) smaller in diameter than 225/50-R18 tires and the speedometer difference is 3.7%. Feb 7, 2023 · 2nd: 2015 AZ 225/40 R18 Summer Tyre Test (225/40 R18) 2 nd : 2015 Auto Review Summer Tyre Test (225/45 R17) 3 rd : 2015 EVO Magazine Performance Tyre Test (225/40 R18) 225/40-R18 tires are 0.82 inches (20.9 mm) larger in diameter than 205/45-R17 tires and the speedometer difference is 3.3% 225/60-R17 tires are 0.89 inches (22.5 mm) larger in diameter than 225/55-R17 tires and the speedometer difference is 3.2%. 8wYfwmE.