I want to put the 6th gen 18" maxima wheels on my 02 max and was wondiring about tire size to get. A lot of people have said to go with 245/40/18 but some tire shops are saying that that size is too wide for a 7.5" wide rim. Do you guys thing that I should get the stock size 245/45/18? or is that too big. Does anyone have those wheels on their max and what size tires are you running? Any advise would be great.

 

245/40/18 and 245/45/18 are the same width.....

the "245" part is the tire width.
the 40/45 part is the profile height (it is a % of width)
the 18 obviously is the rim size.....

 

That is true as far as the tire width, but I know from experience in looking for wider rubber that strangely enough a 235/50/17 is OK for 17x7 rim but a 235/45/17 is not (according to tire manufacturers), so profile does play a role. Checking Michelin's website, the rim width for the 245/40/18 Pilot Sport A/S is 8"+ and for the 45 series tire it is 7.5"+. Count on Nissan to cheap out by going with the narrowest rim

 

that's because if the profile is lower and you go wider, the sidewall angle will be far from "vertical" and apparently that's no good. A little more sidewall in the same width results in an angle closer to vertical.

hmmm...what a bad explanation. But I need to go drink now, no time to rewrite it!...

 

No, your explanation is perfect. It makes complete sense. If they're far from "vertical", they'll wear out too fast blah blah. Happy drinking!!!