275/40-R20 tires are 0.94 inches (24 mm) larger in diameter than 245/40-R20 tires and the speedometer difference is 3.3%.
According to a tire size calculator 245/40 is closer to stock so you would have a more accurate speedometer. I imagine a 245/45 is a more common tire size and will be cheaper. Its nearly hair splitting differences between the two of them, go with the size you get the best price for. 2003 Altima 2.5s (150k & going!)
In the tire comparison table above, you can see a detailed calculation of the size difference between 225/45 R18 and 245/45 R18 tire. The calculation results are presented in the form of visual infographics, on which tire with size 225/45 R18 is on top, and tire with size 245/45 R18 below. Both in the table and in the graph, the tires are
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In this example, the height is 40% of the tire’s width. R: This letter indicates that the tire has a radial construction. 18: This number represents the diameter of the wheel (rim) in inches. Our Observation The differences between 235/40R18 vs 245/40R18 tires are relatively minor. The 245/40R18 offers slightly more ground clearance and a
Ordered 4/8/18, Delivered 8/2/18: 2019 Mustang GT Premium, Ruby Red, 401a, Magneride, 19" Nickel Wheels, Security Package, Roush Axle-Back Exhaust
. 426 469 183 21 472 165 227 110
difference between 245 40 and 245 45
