i checked my oil recently and i found that its over the top dot. i think its .5 litters above what its supposed to be. for the last two oil changes, i put in 5 liters. but i think im supposed to put just 4.5. ive been using 5 liters for about 6 months now. what would be the harm in having an extra .5 liters of mobil 1 sythetic oil in the engine? im due for a oil change so i will be changing the oil back to 4.5 liters.