Unfortunately one of you statements is contradictory. Polishing the cylinder
walls to a much higher degree lessens the chance of oil to lubricate as it
would be wiped off, not having the minor 'indentations' to adhere to; unless it
is a pressure lubricated interface. A porous metal cannot be polished more
than a less porous metal just by definition. A bearing surface profilameter
test would confirm this, a standard surface finish test would not be appropiate
for this situation.

On a similar subject, I know of many automotive engines/transmissions that were
in service far beyond the 12,000 mile warranty. Manufacturing warranty has no
direct correlation to component/subsystem design criteria. It is a marketing
decision. At least it was for the automotive/marine manufacturing companies I
worked with.