[sambam]

Agree, don't wait. It is definitely a roll of the dice. You may make it ok, and you may not. I decided to wait a year before replacing and it almost cost me. Proper inflation, keeping speeds under 65, balancing the weight evenly is all good, but in the end may make no difference with these inferior tires. AND, I probably had fewer than 2000 miles on those Marathons. My Montana is one of the heavier ones, but as a weekend warrior, we travel light. Based on my experience and that of many others, I'd replace them. The peace of mind is priceless. I also suggest a tpms system, whether you make the change or not.