A few maintenance questions

The solution is a rebuild which makes the engine decent. Hg replacements will otherwise repeat as seen in taxi operations. Toyota used the 1.8 L 2ZR-FXE engine worldwide until 2021 in the v/+/Alpha wagons with huge numbers sold in Japan.

 

What solves the hg issues?

 

A better hg was engineered and vastly reduced hydrocarbon build up in the cylinders,intake, pcv and egr.

 

How would it do that? Are there any tests, studies?

 

Not that are available to the public, to be sure.

The first part of his statement is undoubtedly true: A better head gasket was designed.
Maybe as part of a "point issue" upgrade of the engine.

The second part is pure BS as head gaskets don't contribute to carbon buildup......anywhere on
anything.......as long as the gasket hasn't lot it's integrity (blown and leaking).

 

Excessive oil consumption eliminated

 

Strike two.

A "better" head gasket does NOT alter the oil usage........
unless the original one has failed and sprung a leak.

And even if that IS what happened, the oil "consumption" likely is
not the first thing you will notice.

 

Eliminated by a rebuild. I understand the reading comprehension confusion I may have caused for certain folks.