Originally Posted by 07rangersport
Your truck had synthetic oil from the factory. If the oil you put in wasn't synthetic then it probably didn't have the right API certification(in your owners manual). There's no 'synthetic break-in period' in new vehicles anymore. I've been running mobil 1 5-30 and a K+N oil filter since 15K no prob. There's no problem with running 10-30 instead of 5-30.
Nope. Ford only uses Synthetic Oils in their High performance vehicles. That's from their High performance vehicle service manuals. They still use 5W20 and 5W30 in their trucks. Then you'll see Mobil 1 triple synthetic 10W30. The Lightning, a few F150's and 250's use that oil. Motorcraft which is conventional oil not synthetic is used in the Ranger and a few of the F150's. The diesel trucks use 15W40 Rotella, and Mobil 1. Nothing wrong with using 10W30 at all. In fact you get better MPG's using it because it takes longer to get up to temp therefore it runs cooler. But at operating temp they flow the same.