My "new" '74 Duster- or why I need a project like a hole in the head
Good grief.
A Conti EC Sport 02 275/35R18 spec's out at 9.4" tread width. My current Cooper tires spec at 8.1". An RT660 245/45R18 spec's out as 9" tread width. Not far off the 275 and almost an inch more than my current tire. And a Rival S 1.5 is a full inch wider in tread width than my current tire.
So depending on which brand 275/35R18 you compare, there are some 245/40R18 tires that are almost as wide.