I just bought this car and i have no idea what type of gas the previous owner used in it but it takes premium and i always fill at shell but i couldn't find a shell station close by so i filled up with bp premium but now its getting low on gas and i wanna fill up with shell vpower is it ok to mix bp with shell gas as long as its premium? i really wanted the gas to get close to empty so i can fill with shell v power like i always do but its winter and i dont wanna leave the tank low.