I think a lot depends upon how much electronic stuff is on your vehicle, how cold it gets where you live, & the number of batteries in the vehicle. I have a 99 dodge/Cummins diesel and like the other guys here with them, I got phenomenal life out of the stock batteries. I had over 300,000 miles on the truck and it was 11 years old when I had to replace them. I think t helped that there were two batteries so it lessened the load between them. A 2005 Toyota Camry I had went through 4 batteries before I traded it in 2014, but it did have 300,000 miles on it.
I worked at Sears auto center putting on tires and installing/testing batteries when I was in college. There was a definite uptick in bad batteries when they got to be 5 years old. They seemed to be on their last legs after that.
