your car engine runs with oil, drain oil and engine will die. engine health is based over oil grade / quality used. JDM vehicles are poured with single digit temp rating
so whatever lubricant grade you have used so far stick to it change the brand change the drain interval. in Pakistan use oil grade based on average outside temp of your area, it is your car your money and it shall be your choice.
0w-15 Mobil is available for 1 gallon tin price is Rs. 6000 in Karachi., anyone can buy from Plaza autoparts market