The Crossfire is my first synthetic oil vehicle. With all my prior vehicles, I got the oil changed "every 3 months or 3,000 miles" - because I take the subway to work, more often than not I hit the 3 mos before hitting the 3K miles. The Xfi owner's manual says the oil change (with A or B service) should be done every 7,000 miles (less with harsh road conditions). I get mine done every 5,000 miles to be on the safe side given D.C. road conditions (lots of short trips & stop and go traffic). Today is June 2, 2007 and I got my last oil change/B Service in January 2007; in that time I've only put 2K miles on it. Is there any harm in waiting until 5K miles for my next oil change?, or do I need to change the oil now by virtue of time elapsed? It may be the end of the year before I hit 5K miles. Is a year too long to go without changing the oil so long as you're honoring the mileage-based service interval? The manual doesn't address this & I don't like that.