Who says they are 70/30. And honestly who cares what the ratio is. Look at what manufacturers approvals and what specs it meets,then judge.
If I can get a blended oil that is every bit as good as its synthetic counterpart,for less money why buy the synthetic. That makes no sense at all unless you like to spend more to go the same distance.
By the true definition of synthetic M1 0w-40 isn't one,and is labelled as such in Europe yet it carries more oem certs than any gasoline engine oil I've ever seen. Is it in some way inferior of its true synthetic counterparts and in real life driving would anything other than your wallet know the difference.
But that's just you is it. You want to spend more for a lubricant I guess. Does that make you smarter in some way.
And while using these real synthetics do you actually use them to extend the interval,or are you one of those "peace of mind" guys.
6000 miles isn't an extended interval.
The cars in your sig shouldn't have any problems with a 5000 mile interval on conventional,unless that cavalier is pushing 20 pounds of boost or that rodeo is spraying a 150 shot,or is there some other reason you need a full synthetic,that isn't a blend.
Personally I'd be more interested with what specs the oil has been proven to meet then compare that with the cost of other oils in that category,then buy accordingly,because I like money much better in my pocket.
But that's just me.
Good points and I agree with you 100%.
Running 5K OCI on all my vehicles with Havoline High Mileage which I got for $12.99 a 5 quart jug. First time using this oil so it's a test phase for me. The only vehicle that gets Synthetics is the 04 Ascender in which I then run a 10K OCI. I have used PP, Napa SYN, Valvoline SYN, and Amsoil.