I have been looking madly at tire size website's for a couple weeks now, and have noticed that when looking for 275/40/17's it also calls for 275/45's?

So my question is this, should one be looking to get 275/45 or 275/40's ? I see alot of people go with the 40's so wasnt sure the difference is or what is correct?

 

you want 275/40/17 that is the correct sidewall height.

 

Noob question...what do the first 2 numbers stand for

I'll take a stab at it and guess that the first number is the width of the tire and the second is the thickness of the sidewall???

 

yeah the in the case 275 is how wide the tire is, and the 40 in how tall the side wall is...

 

I figured (40) were the correct sidewall, just was curious on 45's so thought I would ask.

I get the new set installed tomorrow, they are Nexes 275/40's x4. Never heard of these before so we'll see, but from what I have read is that they are a German based tire that are mounted onto BMW/Mercedez Benz cars. They seem to have the same tire pattern almost as a Falken tire but are a whole lot cheaper!