I just purchased some after market rims which are 17"x7". I have an LS and i believe that the stock tires are 15"x6.5". The tire size i have now is 195/60/15 and i used a tire calculator to figure that i think i need 205/45/17 but im not sure if that is correct with the width of the rims being different. Can someone please help me straighten this out so i dont get the wrong size. Thanks

 

Well im getting some 17x7's and the rated tire size on the website for all their 17x7's are 205/40/17. You could also use a 205/45/17, that just gives you a larger wall.

 

put some 215/45/17s. Those should fit. whats the stock rim width for the SS/SC?? tthey have 215/45/18 but can goto a 225

my 18s on my old car were 245/40/18

 

yea but the thing is that the calculator told me to use the 205/45/17 so that the speedometer isnt off very much. Any other size seems to throw it way off. I just want to make sure a 205 tire is wire enough for a 17X7 rim

 

Yeah 205/45R17 is no problem on a 17x7 wheel.

Here is a good tire size calculator that includes recommended rim width.

 

According to TireRack.com for a 205/45/17 the prefered size is a 7" wide wheel. That will also put you at a 0.21% speed difference when 3.00% difference is still regarded as ok.

You could go wider, but the 205/45/17 and 17"x7" are a match made in heaven.