Serpentine Belts 101

I dropped my car off at the shop today to have both serpentine belts replaced. I have a supercharged car, so those babies aren't cheap! I was pleasantly surprised when I went to pick my car up that the bill was $20 cheaper than originally quoted (which makes it $95 cheaper than what the GM dealership was going to charge me). Can't beat that!

In doing a little reading, I found out that my belts were WAY past due in being replaced. Apparently, a serpentine belt is made to last 30-40K miles. My car is at almost 85K, and I bought it new so I know they've never been replaced. LOL, yes I consider myself lucky.

I asked the mechanic, "How bad were the belts?" (This was before I edu-ma-cated myself with some info.) He actually went and dug them out of the trash. They sorta looked like this... only MUCH, MUCH worse:

I've read that some (horizontal) cracks are OK, and normal. Excessive cracks, chunks missings, or lateral cracks are NOT OK. Obviously, my belt fit into the latter category. :(

Here's what a new belt looks
like next to a bad belt

Just what IS a serpentine belt? I had no idea, until I did some research. It's a belt that drives the components of the engine such as the alternator, power steering pump, water pump, air compressor, air pump, etc. It's what keeps your battery charged (oh really!), your engine cool, steering easy to turn and keeps you cool when it's hot enough to cook eggs on your sidewalk.