'87 944 n.a.

i've been maintaining my phone-dial wheels w/ petroleum jelly coating,
seems to be pretty good - brake dust wipes clean off - but in some
spots they are slightly yellow/plastic-looking, in contrast to the
nice shiny aluminum proper appearance.  i treated them with various
things in the past, wondering if i wore a layer off or what (pls. ask
for more info) - what exactly are the metals in the wheels anyways?
thought they were mostly aluminum.

-bryan