Rear tire sizes: 305/45-18 vs 305/40-18

[///Bruce]

If you look at Nitto 555R's, the 45 will fit on a 9.5" rear. But the 40 will not fit unless it's 10" wide. Anyone get the 305/40-18's to fit on a stock 18x9.5 rim?

 

[black99lightnin]

makes no sense. 305 is the width. 45/40 is the height as a percentage. The 45 is pretty tall and what is used for Lightnings.

 

[///Bruce]

I thought the same thing. But look at Nitto site. The 45's will fit on a 9.5" rim but the 40's begin on a 10" rim. It might be because of the additional width.

Why I would want to do this is because the OD is right at 27". Perfect diameter relative to the front size.

 

[stkjock]

the bigger aspect ratio allows a fitment on a narrower rim due to the size of the side wall.

the 40s will fit on a 9.5" but it's less than optimal and will bulge more

 

[///Bruce]

Thank you for the explanation. Now the questions begs will the 40 fit with no rubbing issues...