I just blew out a tire on my car. The tire says it's 225/45r18 .. Is that a somewhat low profile tire? I have it on a set of 20's. Basically what I'm asking is if 225/45r18 can be just a low profile tire? Or can it also range from being a thick tire to a low profile tire? Idk.. How do tire sizes work?
No, actually you do not have it on 20's lol however, yes that is a low profile tire.
Sorry, you don't have a 225/45 R18 on a set of 20s. Your wheel size is 18".
No way did you get an 18-incher on "a set of 20's." In this forum, we obey the laws of physics. Look closely at that "45." That means that sidewall height is 45 percent of tread width. A lower-profile tire might be a 40 or 35. 50s and such are taller.
It is physically impossible to mount a 18 diameter tire on a 20 inch diameter rim. You have 18's. Secondly, any tire with an sidewall aspect ratio of 55 or less is considered by most a low profile tire.
Decoding a tire sidewall: The first letter (in your case, probably a "P") represents a "passenger" vehicle (car) tire. The first number, the "225" is the width of the tire at its widest point in millimeters, when mounted on the correct size wheel. The second number, the 45, is the ASPECT RATIO between the height of the sidewall and the width of the tire. In this case, the height of the tire's sidewall is 45% of the width of the tire. The lower this number, the lower the profile of the tire. As an example, the sidewall height ratio for a regular passenger car tire is around 70-85, meaning the height of the sidewall is 70% to 85% the width of the tire. (So, if your tire is 225 mm wide, the sidewall will be 45% of that high, or 101.25 mm high.) The "r" designates a "radial" ply tire. The last number (in your case, 18) indicates the tire will fit onto an 18 inch rim. So, as another poster pointed out, if your tire is a 225/45r18 then you have 18-inch rims.
