Look, if it costs $2.00 per quart, it is not synthetic. If it doesn't last at least 15,000 miles between changes, it is not synthetic. What it is is hydrocracked dino oil. Major difference, it lacks the lubrication qualities, the oxidation resistance, and thermal resistance of real synthetic oil.

 

Yea I guess youre right. It makes no difference that Walmart puts SYNTHETIC right on there. And yea, the lubrication qualities do suck....it doesn't burn any oil at 130K, but I know...it will by tomorrow morning. Wake up.

 

Supertech oil is GP III oil and is a full synthetic according to the API terms. Castrol is also a full GP III base stock. Castrol costs 4.00 more a quart and so far the UOA's are kind of low.

 

Yep. The difference being Walmart works off a tighter gross profit margin (but makes it up in high volumes) and Castrol has those pretty slick color magazine ads.

 

You know what. The only Castrol synthetic I like is GC 0W-30. All the GTX is good. No one can say they aren't. But, this new GC (gold) is not impressing me. It does great in some things, but it doesn't seem to be a good oil for everything. Not that all oils are, but GTX does good most any street car. Not talking about big turbo set ups or high horsepower V8's... just saying, what most of us drive.