My marathons say 50 psi is max. I keep at 42 psi. I think a blowout would be cause less damage with less psi. I've never heard of your MaxTow brand but I think you'll be fine for one more year. Some on here think you should get new tire every couple of years which is waste of money in my opinion. I know some here have replaced 6 year old tires that never gave them a bit of trouble only to go out on the new tires and have a blowout on their first trip! If you have a spare and continue to watch for cracks you should be alright.