Hmmm I recieved some leftover oil from a friend which was a couple of 5qt juggs of castrol 0w40 and 6 1qt castrol 0w40. The 5qt juggs says they are made from belgium yet the 1 quart single bottles are made from Germany, both EU formula. My car takes 7 quarts so I figured I use One jugg and 2 single quarts. Is it ok to mix them even though ones from germany and ones from belgium? Thanks