The 2019 C7 manual calls for tire rotation (p. 279) after 12,000 km or if unusual tread wear is detected, and side to side only for different tire sizes. For a C8, my dealer said NOT to rotate tires at all, when I asked him about doing it side to side which is the only possibility given the different front/back tire sizes. Oddly enough, after picking up the C8 I noticed the 2020 C8 manual (p. 259) says to rotate tires (same size only) after 12,000 km, with much the same wording as the 2019 C7 manual and I've never asked my dealer to explain that discrepancy. For my 4-door sedan "winter vehicle" I was told to only rotate tires front to back, as done by Rruuff Day for his truck. I do that each time I change the winter grips for all-season and those are also all speed rated tires. So perhaps this is open for debate/opinion, given people's comments about NOT rotating due to the directional nature of high speed rated tires?? But if that's a concern, why don't the Corvette manuals say different?