It's only got 28,000 miles on it. I did it based on time, 8 years, not mileage obviously. A mechanic that I like and trust had recommended doing it at 8 years, and he's getting fairly close to retirement so I just thought I would do it while he was available.
The American maintenance schedule only recommends doing it based on mileage, which I will never get to. I had found a European service schedule for our cars that recommended doing it at 10 years or 125,000 miles, whichever comes first, so I wasn't that early on that schedule.