I use lighter flavor olive oil. Most likely not 100% Primal, but I can't tolerate the too strong flavor of the extra virgin kind. At any rate it's a huge step up from the soybean oil mayo sold at the store.
It lasts about a week, stored in the coldest part of the fridge. But ymmv, because I follow the principle, if it doesn't stink too bad, it's ok to eat.