I'm looking for input or opinions on who all follows the tire replacement recommendations of new tires every 7 years. The chief feels the need to follow it due to possible liability, but would love evidence to avoid the cost. I'm trying to find a way for us to scrap that idea. I've already found the NFPA TIA proposal and the Tech Committee votes to throw it out.
Funny you should be writing about this event. I just went through this with my department recently.
On how much tread is allowed on any Vehicle per DOT (Department of Transportation)
We just went through the same. Talking with the mechanic, he said as long as they are showing no unusual wear, to keep them. They don't have an expiration date. If the sidewalls show cracking, then replace them. Some of our rigs just don't get the miles to wear them down. Have them inspected by a mechanic or tire shop if you feel unqualified to do so.
We do it due to the fact that while the tires may look ok from the outside they may have wear and tear on the belts for those that are radial belted tires that you cant see. One thing you may want to look at is State and Federal DOT regs for emergency vehicles. At that point if its in those regs that you have to change them every 7 years you are kind of stuck changing them.