The 13.6x28 tires are the 'stock' size for that tractor.
Personally... I'd stick with the 28"s... I guess, since you're kinda stuck with buying one tire anyway... it'd be prudent to see which tire size is more readily available... and more economical. Maybe base your decision on that?
Personally... I'd stick with the 28"s... I guess, since you're kinda stuck with buying one tire anyway... it'd be prudent to see which tire size is more readily available... and more economical. Maybe base your decision on that?