In reply to Aquatic Tacoma's comments, I'm not meaning to be offensive, but if you had all those problems there were other things going on.
Unless one has a vehicle that has been severely neglected (ie, infrequent oil changes), synthetic oil is just fine, and you can convert to synthetic anytime.
I've never had problems switching a vehicle to synthetic, and I've owned many vehicles over the past 35 years.
Having said that, I don't like to get in the middle of the synthetic vs dino fluids debate. I personally use synthetic....but as long as you perform regular oil changes, either is fine. I prefer synthetic due to several advantages that it has...but it does cost more...BUT I can go for extended drain intervals and the additional cost is well worth it to me.
My 4.3 liter chevy V6 has 308k miles, runs like new, uses one quart of oil every 6k miles, get great fuel mileage, and has never been opened.