Synthetic or Regular Oil??

I've always used regular grade oil (5W-30) on my 01' Century for which I've been the only owner, now the car is approaching 100000 miles and my friends have recommended that I switch to synthetic oil as it would protect the engine better against wear and not cause oil sludge residue a known engine killer. My question is if it would cause any engine damage if I do so when the car has used regular oil always. Would it make the engine last longer If I do so?

Switching to synthetic oil will "clean out" your engine, and protect it better. Many people switch to synthetic around 100,000 miles. Here is a link to another post in another forum on this site which has some good info on using synthetic oils,http://www.automotiveforums.com/vbulletin/showthread.php?t=470834

I used to sell Amzoil synthetic oil when I lived in Nebraska. Out here in Michigan I use Valvoline Synthetic. I'm not down on Amzoil, it's just that the darn Valvoline Synthetic is available at Wal-Mart and Autozone around here. It makes it more "accessable" when you look for oil for changes or adding.

Personally I'd always use the higher priced synthetics because they create better wear tests in labs, and they produce better gas mileage. Your engine surfaces "float" on a film of protection afforded by oil. The better it glides along the less your engine wears.

I also like the higher TBN (total base number... detergent action) of the Valvoline 10-40 and the Amzoil.