Originally Posted by fthopkins
Please please please don't think I am trying to start a fight. I am NOT. I have heard for years and years to replace my tires every 7 years no matter what. And I do. But I have always wondered if this is something the tire companies came up with (I'm a very suspicious man) or where is the data? I Know there are some very smart people on this form, so I figure someone will likely post a link.
How much to your tires sit and how much do they move?
How fast do you drive when towing?
How much sun do they get and how bright is the sun?
How many curbs do you hit?
How well do you watch your tire inflation?
How hot does it get where you live and for how long?
How cold does it get and for how long?
How good a tire did you buy?
How good a tire did you actually get when you bought it?
(yes this can go on and on).
Since nobody ever has the exact same answers to the full list of variables, there is no one single answer to the "how long?" question. Folks most certainly see wear out issues with tires before the magic "5 year" limit. Others *seem* to roll down the road on much older tires without winding up in the ditch.
All that said, the tire guys aren't lying to you. Don't run old tires.