I own a lovely 2002 ES300. I have faithfully followed the maintenance schedule. The car now has 82,500 miles. The maintenance book indicates that the timing belt should be replaced at 90,000 miles. I grew up in the old days of timing chains when this never even came up. I am retired and and am not hard on the car. Question: Do I really need to spend the money on a new timing belt or is this just a "recommended" item.