Hyundai Repair: General Maintenance, balance shaft, timing belts

Question
Got the reply on my last ?. You may have guessed I/m no mechanic & have little car knowledge. MY H 2001 Sonota manual states 7500 for oil cg., many people say 3,000, I use in the middle 5,000. Is that reasonable? Also is it also necessary to cg. a timing belt as recommended? Thanks again in advance for your reply!

Answer
5,000 miles isn't unreasonable.  My personal preference is 3,000 miles, and that's what I do on my car.  But there's significant debate even among professionals whether that's actually necessary.

It's Hyundai's recommendation to change the timing belt at 60,000 miles or four years, whichever comes first.  On the 2.4 liter four cylinder, it's extremely important to replace the timing and balance shaft belts at that interval.  I've seen numerous timing belts strip on that engine in close proximity to the recommended interval.  When that happens, engine damage is likely.  I've never seen nor heard of a failure on the 2.5 liter V6, so I'd expect you can actually get significantly longer than the maintenance interval out of the belt.  How far you can stretch it, though, I have no idea.  The bottom line is, the longer you wait, the greater the likelihood the timing belt will fail and cause engine damage.