My ancient, but awesome and indestructible 1991 Volvo 740 SE (special edition turbo), currently has four Goodyear Eagles bought new in October 2015. I checked the week/year of manufacture on the sidewalls before I agreed that my mechanic would put them on my car. All were manufactured within six months of purchase.
Now, living in SoCal (a hellhole), they are showing age cracks on the outer treads. There are no cracks on the sidewalls. Given that the tires are less than four years old, and the crack distribution is limited, is it time to replace them already?? (Treadwear is minor as I drive only about 7000 miles a year) Articles online claim that 10 years is the absolute maximum for tire life, but replacemet every six years is safer. Still, can the SoCal sun, and ground-level ozone (worst in the nation) fry my tires in less than four years? Should I replace them now?
Also, I've heard that tire sealants can prolong life of tires with age cracks--is this worthwhile? I will be seeing my mechanic tomorrow for routine maintenance. He is a very good mechanic, and honest, but still, these guys are always pushing you to spend more money! Would appreciate any thoughts on this. Thanks!