To be exact, our car has a 4.3 qt. capacity so, adding 4.5 quarts will be just perfect. Mobil 1 is a great oil but, have you thought about using Royal Purple or Redline 10W30's (probably 10W40 if with a turbo kit)? If you drive your car HARD, then I think the extra expense is worth it. Just my 2 cent
~Fly1
___________ Kon C
"Sometimes, a man has to do what a man has to do."