I have said it before and I will say it again---there is no such thing as fully synthetic motor oil. The base oil is natural petroleum oil. It's only the additive package that is either synthetic or parafin based. Yes the synthetic additives hold up better and longer, but they are not more slippery that the parafin based additives. We ran a test a few years ago with an electric motor and a pair of steel rods. One rod was attached to the shaft of the motor and was spun; the other rod had an attachment for a torque wrench and was hinged. What you did was spray your oil of choice on the rods and then see how much torque it took to stop the motor from spinning by levering the hinged rod against the spinning one. We tested all available oils and additives at the time. There was only one additive we used that you couldn't stop the motor at all---ALL the other oils and additives showed the exact same torque to stop the motor.
That being said--I have been a mechanic for over 20 years at this point, and I have built many motors and trans' and diffs for many different purposes. I have over the years used many different brands and types of oils and additives. I just did oil changes on my wifes car and my 8.1L Suburban that I use for towing and I am due to change the oil in my 5.0 Mustang--they will all get the cheapest oil I can find that meets current SAE SM standards--same as the boats and both lawn mower and tractor--same as the snowblower and the 10.5 hp pressure washer--same as my 383 powered, nitrous injected Camaro. Why? you may ask--because after all these years, the one thing I have discovered is regular maintance is all that is really going to preserve any internal combustion engine over the long term. And wasting money on B.S. marketing hype and name brand is just that--waste of money. Just my opinion--but a well researched one.
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Stan
