If you are still getting good use from an eight year old battery, you are very lucky. My car is an '09 and I am on my third battery. Original, and two replacements. I live in Florida and hot climates seem to be very hard on all car batteries. On the 451, battery placement makes getting to it more difficult than most cars. I have found replacing my battery every four years as a preventative measure gives me the piece of mind I need at my age.
