There's a few noteworthy advantages to using a full synthetic motor oil. As long as you don't put it in too soon. That's why I recommend waiting for at least 5000-6000 miles before switching over... maybe even 8000 miles. However, not all synthetics are created equally and some oils work better in some engines, while others can be detrimental, depending on the make (for instance Royal Purple in a Nissan VQ35HR engine is a VERY bad idea). A good (i.e. real) synthetic offers a molecular advantage (most molecules are roughly the same size) so they offer better stability at high temps (bigger molecules don't make sludge while smaller molecules don't get burned off). Also contaminates are held in suspension better on a full synthetic. A few synthetics actually do provide a reduction in friction, which equates to longer service life, less heat related wear, and yes even a smidge more power. Synthetics are also better in turbocharged vehicles due to reduced chance of coking (the main reason people use a turbo timer). As I'm sure most of you know, shutting off a car with a hot turbo can cause the oil to boil and coke inside the turbo, which can cause all kinds of issues. FWIW, I'm using Kendall 5w-20 synthetic blend for the first 6000 miles and then I'll use Pennzoil Ultra 5w-20 or something else. No Mobil 1 or Royal Purple for me... A few years ago most of the major synthetic oil makers like Mobil, QS, Pennzoil etc., changed their synthetic formula (and I'm not about to get into specifics) but lets just say it's not nearly as good as it used to be and leave it at that. That's because Federal rules regarding synthetics changed. Most are now just base mineral oil processed until it meets those new standards. "Processing" mineral stock base does NOT make for "man made" unfortunately. I don't know if RP has change their recipe in recent years but a few years ago they had some questionable additives. Ford recommends a 5w-20 synthetic blend or full synthetic for our Fiesta STs. Their oil is actually pretty good (and their manual transmission fluid is REALLY REALLY good). I have no idea who FoMoCo gets their oil from.