Blade Runner / FAQ / Four
Did Tyrell Lie to Roy?
Tyrell probably means they couldn't risk making him any better because
they can only control them for so long. This assumes Bryant is correct in
saying the 4-year lifespan is intentionally built-in. Tyrell also says
"the light that burns twice as bright..." suggesting improved performance
may be a trade-off with lifespan. Since Tyrell's goal is commerce, he may
have turned a biological problem into a benefit by taking advantage of the
4-year lifespan -- planned obsolescence. When Sebastian says, "There's
some of me in you," he might be referring to the intentional use of the
genes responsible for Methuselah Syndrome.