dino oil shearing out of grade from normal driving

[hondaintegratypes]

a friend of mine told me that in some toyota corolla, the valvoline or quaker state dino oil sheared out of grade after about 30 min of normal driving.

is that possible? are dino oils really that bad? i understand that you shouldn't use them for racing, but i thought that they would at least give you adequate protection for normal driving.

with the latest ILSAC GF standards, even dino oils perform well. shouldn't they?

 

[ToyotaNSaturn]

Sheared out of grade in 30 minutes? Big NO on that one. There was some talk about how thin oils meet the fuel-efficient GF spec's by shearing back to the 20wt range rather quickly. Perhaps that's what he's referring to...??? But this really doesn't happen all the much anymore.

Maybe if he mistakenly grabbed the SA or SB rated oils at the local WalMart and saw this happen, but not in a SL or SM rated oil. Even the cheapest SL/SM products will stay in grade for a couple thousand miles unless there are other mechanical issues in play.

 

[Quest]

LOL! Another one of those urban myth or legend....