do tires lose their umph

Luke, another question. when and if do tires lose their umph? not making much sense, ok then. i have an 89 suburban with 55k original miles. i have a set of goodyear/workhorse tires which were installed about 5-6 years ago. because the vehicles doesn't get alot of use do the tires ever go bad and just need to be replaced. i know that tires do dry rot, but my vehicle is 99% of the time in the garage. just wanted to know incase i decide to take a long trip. thought maybe they lose their elasticity.

Tires do lose the gripping ability especially in the wet as the rubber tends to harden up as the tire ages.

Whenever a tire is exposed to hot and cold swings such as those caused by normal temperature changes as a vehicles sit in a garage this simulates what the temperature changes tire experiences during normal use.

[email protected]