I've had a quart of Amsoil and Mobil 1 sitting around my garage for about 3 years. Both are unopened GF4 5w30. Since my 1.8L Toyota engine only takes 4.5 qts I've got about 3 qts of PP GF5 5w30 I've collected from leftovers 5+ qt jugs. Does anyone see an issue if I combine it all and for my next change?