No doubt.. the feds said reduce the oil globs going into the atmospher by recycling it in the motor.and you meet the standard,.. and then they kept twisting the noose and the standards got more stringent and that led to better fuel metering, better fuel economy and cats and more... but more technically different engines.It also had to do with emissions. To keep oil from going into the cylinder and being burned. It worked well.
But in 1990 on the motronic injected cars. Alfa had to add valve stem seals on the exhaust valves to eliminate the very small amount that would leak by.