I changed my oil 2 months ago and decieded to use Amsoil.which it says on bottle that its good for 25000 mile/ 40000 km OCI. Anyone ever run it that long? I so far have 10000 km on it and level is still full and barely any darker. I know darkness has not much to do with it but...I have ran Mobil 1 EP for 15000 km so I would think maybe amsoil could last 40000km Any thoughts???