My 2010 Fusion SE has 44,500 miles on it. It is the 4cyl. model with a 6 speed manual transmission. I have had the oil changed every 4-5,000 miles, never had any issues. Today when I went in to get the oil changed the guy told me a synthetic blend is required, and he wanted to charge me an extra 20 bucks for the oil change. I looked up in owners man. and it says SAE 5W20 and some Ford nomenclature for the minimum requirements for quality, etc. My question is this, why haven’t any of my other oil changes required an up charge to a more expensive oil? I would have noticed. Does this car really need synthetic blend, and if so, is it really better than conventional oil? Have my previous oil changed damaged the car?