5-Quart Castrol Edge Full Synthetic Motor Oil: 5W-30 $18.35, 0W-20 Expired

If you look at my previous post I get into the chemistry differences but basically the difference between a premium synthetic (M1, EDGE, PP) and an entry-level synthetic (SuperTech, Amazon, Costco) is the choice in additives they use.

When you want to make an entry level synthetic, you take a cheap conventional "market general" additive package that meets API SN Plus / dexos1 and make it in Group III. Market general means it's available to anyone hence why those products are actually identical and when additive companies develop these additive packs, their goal is to make the cheapest pack that still meets spec and lowest cost/treat rates get the big volumes like Costco and Amazon.

When you make a premium product you have a custom additive package and you target your multiple specs (ACEA, VW, MB, BMW etc.) and what your marketing department wants as your "differentiator" so be it better wear performance or sludge protection etc. These additive packages are proprietary and also have more liberty to use more expensive, better performing components. So fancier antioxidants, unique antiwear chemistry beyond ZDDP as everyone is limited to 800ppm, more dispersants and more exotic detergent mix. The VM (viscosity modifier or polymer) choice is also a major difference as the preference goes PMA > Styrenic > OCP which applies to performance and cost. OCP is your cheap and what I call dirty VM as it tends to break down and leave piston deposits at high temp areas like turbo bearings. Styrenics burn much cleaner and don't leave as much deposits but you need to use more than an equivalent OCP.

That's the difference. so in this case for $2 more I wouldn't hesitate to buy a product with easily double the additive amount and the nice clean, shear stable VM that doesn't leave piston deposit. I'm not sure if they make much money at this price as I think it may only cover variable cost and none of the R&D or licensing fees.

Well you're mostly right in that you shouldn't be able to feel it, but technically frictional and pumping losses in your engine waste around 10 - 15% of your power. So better friction modifiers, higher viscosity index fluids like synthetics can reduce those losses and reduce power loss. We had worked on an oil for a Nascar team that was designed to give them a teeny tiny competitive advantage once but still had to protect for 500 laps. That was fun and hard, they use some really new age tech in old school engines.

Probably the easiest way you feel it is if you crank your car over in the super cold with a conventional oil vs. a same weight synthetic. Your engine will crank over faster, may rev a little smoother but really these "feel" things are almost impossible to discern. That's why I said you aren't wrong.

BTW GM dexos1 is pretty strict but it is a minimum performance spec that almost any AP SN Plus oil can meet. However they charge royalties to use the dexos1 label so hence why many companies may meet it but not claim it. Extra revenue for them, more cost for you.

BBTW I know you folks find me chatting forever on these forums and that's only because I formulated this stuff for years so it's kind of my hobby. Ask me anything you like or just tune me out as the tech geek =)

Yeah, assuming same weight oil, oil doesn't make a car "more powerful."

And just because "Scotty" said something, doesn't mean it's true.