If the oil is black then either it hasn't been serviced in a long time or the oil that was used isn't very good. Cars dealers will do anything on the cheap and if the oil looked ok when they pulled out the dipstick then it ok for them. Friend has a manual 97 VR4 and i check his oil after 10000km from the dealer service, it was black so i'll be changing that for him tonight. I'll be using Mobil 1 sythnetic, giving it a flush too. I change my oil every 5000km and use sythnetic, it helps to protect the engine/turbos from wear. These cars are driven and after 5000km of loving the car it did'nt feel as smooth as the first oil change, you can feel it as the car idles. Once i did the flush and oil change the car runs very smooth.
AYC oil is meant to changed and bleed every 20000km. Just get Mitsubishi to check your AYC oil, they'll will tell u if it's ok or not. The AYC has to be computer bleed by Mitsubishi.