Tire age

Most of our cars don't get tons of miles on them so it brings up the question, at what point, age wise must we get new tires. My car has older tires i am not going to relay their age at this time due to wanting to see everyone's answer.
I have a set of older tires on my car, there are no cracks or splits at all. Still has a ton of tread left. I do have a bit of traction problems when shifting into second during a normal take off and if i get into the pedal a bit. If i try to launch hard from a stop light just forget about getting traction. Before finding out the age of the tire i just figured maybe to much torque and gear for a 225 tire and thinking i just need to go wider. But after seeing the age of the tire i am thinking that has something to do with it.

So at what age does everyone get new tires for good traction and safety?