I have factory 17 inch rims on my car and when i look at the recommended size it says 225/50/17.

What do each of these numbers stand for....i know the 17 is the size of the rim, but what does the 225/50 numbers stand for?

Cause right now i looked at the tires on my car and they are 225/45/17

is this bad that the 45 and 50 are different?

 

225 represents tire section width. (higher the #, wider the tires)
50 represents sidewall height
17 represents the diameter of the wheel.

 

So if right now i have 225/45/17 is it ok that i have 45 instead of the recommended 50? Also, is it measured in MM?

 

The 225 is the tire width (accross the tread) in millimeters.
50 is the ratio of tire width to sidewall height. Since it is a ratio, it doesn't measure an exact number, like millimeters or inches. If you have 45 ratio tires right now, it means that the tires are slightly lower profile than the 50s. Given the same tire width (225 in your case), the lower that number, the less height will be on the sidewalls, so the tires will be lower profile.

It may affect your speedometer or odometer accuracy a little, but I'd think that the difference between 45 and 50 profile tires wouldn't be that great.

 

Give the Tire Rack a call, they can tell you what you
need. If your going with a 45 you may be able to go
with a 245-45/17 and have the same heighth tire.
With an 8" wide rim that wouldn't be a problem!

 

he wouldnt be able to go with a 245 since his tire width on 17s i believe are 7 1/2 inches (not positive on that) he would not be able to go wider than the recomended size because the tire would then be to wide for the rim.....

i have a question though, would he even be able to go down to like a 225/40/17 if they made it? His sidewall would be thinner would it function ok?

 

hm what is the biggest u would go on the stock 17's for more grip but wont slower the car?