anything u do, definitely has pros and cons..
for an example, if u want power.. u sacrifice fuel.
to me, engine dirty.. can clear carbon by driving at high speeds..
140km/h+ should be sufficient.. (im not encouraging pple to speed
though).. service the car.. can also flush ur engine (i think it
will clean ur engine.. but also quite expensive)
but also with proper maintenance and stuff.. i think it shld be
ok..
take those 10-20yr old sports cars on the road right now.. take a
souped up rx-7.. im sure engine will be very dirty with heavy mods
for air intake and stuff.. but its running perfectly fine..
i own a maz6 too.. wanna add an openpod soon and a SRI with cf heat
shield somewhere near december i guess..
well.. its just my 2cents though..