I was looking at TireRacks specs for the Kumho Ecsta XS 275/40-17 and 285/40-17. For some reason, in the "Section Width" column, they both have the same width of 11".

Common sense would tell me that all things being equal, a 285 would be wider than a 275... Why isn't there a Section Width difference?

 

For whatever reason they both list 11" wide section width. I even checked the Kuho site. Normally the 285 would be about 1/3" wider.