TomT.
You get what you pay for.
Most OEM batteries rarely last much past 5 years, and some don't make it 36 months.
My 2001 Sport Trac battery lasted less than three years. After I jump started it and drove to the dealer, I had 35,989 miles on the odometer. I only had 11 miles left on my warranty and I got a brand new battery. I eventually put over 42K miles and turned it back in (leased) and purchased a new 2003.
In the mid 1990's the EPA required battery manufacturers to reduce the amount of lead in their batteries. Since then, battery life has dropped noticably.
The Optima batteries seem to have a longer life than most batteries. They don't use any more lead, but their spiral cell and gel technology appears to work to provide more power and a longer battery life.
I would look at purchasing an Optima battery if I planned on keeping the vehicle for about 3 or more years. It would be well worth the investment to know that you will not have to worry about battery problems.
Remeber, batteries usually die very suddenly. They don't make noise or seem to be weak until the very end., and that typically happens at the most inconvenient time.
...Rich
...Rich