Is 45 a low profile tire?
Fifty and 45 would be considered low-profile, and would have a shorter sidewall. Typically, low profile tyres have an aspect ratio of 50 or lower. This means that the height of the tyre’s sidewall is only half or less than the width of the tyre.
Which tire is wider, 50 or 45?
The 45-50 number is the aspect ratio of the tire, bigger the number the larger the sidewall. Though in this case, the difference is small, around an inch, but still affects final drive ratio as other have mentioned. At low speeds probably off by 1mph and difference increases to 2mph or so at highway speeds. Aspect Ratio): The tire’s sidewall is 45% of the tire’s width, which means the sidewall is about 114 millimeters or just over 4 inches. R (Construction Type): Radial tire, the most common type of tire produced today.