If you use a good name brand oil, change it on a regular basis, you'll never have a problem. The myth that you can go 10-20K miles on a synthetic oil is more harmfull that regular oil that gets changed regularly.
As for me, I run 10W30 or 10W40 Valvoline multi-grade in everything and everything gets used pretty hard. I've never had an oil related breakdown yet. I've been turning wrenches for over 30 years too. The key is to keeping it clean.
Scott
