Sam; Good afternoon to you sir, I hope that other than having some vehicular issues that summer has been treating you folks well.
As noted by others, the photo shows radial cracking and in my experience that's worse than sidewall cracking - well somewhat worse anyway Sam.
Our Okanagan sun is really tough on tires, so it's not an uncommon site to see what you showed - but markedly worse on one side often if it gets more sun.
We had to change out the BF Goodrich TA's on the midlife crisis last year as they were doing the same thing your wife's rig's tires were, but they had at least half the tread left.
Anyway good luck with your vehicle repairs Sam and all the best to you all as we progress towards fall.
Dwayne
Last edited by BC30cal; 07/07/19. Reason: added for clarity - hopefully
