If what you mean is, are there oils that don't measure up to even their virgin published PDS spec's, then yes there are many including so-called premium brands.
PQIA is also constantly finding oils that don't meet spec'.
As to how oils perform is service, the degree of oil shear is an common complaint with some oils and certain oil grades; 5W-50 for example. It may be totally acceptable particularly with OEM oils but some get freaked about it done the less.
Despite all that, the vast majority of motor oils outside of the deliberately fraudulent offerings (that PQIA uncovers)do a fine job. Even the cheapest off brand API oil does a fine job in the right application.
