As long as there is sufficient room in the pan, the oil PRESSURE will not change (thus filling more will not create a leak... in and of itself) Crank foaming will occur with TOO much, and that would be somewhere in the safe range of 7qts. 6.5 qts for the life of my car, before Ross took her in, and she would only burn about 1/4 of a qt in the 4500-5000 mile intervals I used. (I changed the filter at oil changes, and once at the halfway mark..)
