are you talking about transesterificated vegetable oil
http://en.wikipedia.org/wiki/Transesterificationor in other words bio-diesel
http://en.wikipedia.org/wiki/Biodieselor are you talking about pure unmodified vegetable oil
the first, bio-diesel, will sure be no problem at 10%,
50% might work, but is not suggested or supported by
Mitsubishi, warranty void etc...
prime problem here, bio-diesel does not lubricate well
and might be aggresive to the pump
so try not to stress your engine when using a high %
of bio-diesel and your injection pump might fail more
early
the second, just pure raw vegetable oil, will need a lot
of engine modifications, pre-heating and quite some
other modifications
with an ECU driven engine a hell of a project for some
real expert
C.