I have a friend who converted an old short school bus to a live-in drive around camper. She then had it converted to run on old cooking oil. They had a tank for regular disel to start it and once hot, they flipped it over to the used cooking oil tank.
They learned though that trying to filter old cooking oil on the road is tough....and nearly impossible in colder temperatures to keep it liquid enough to use....
But that shouldn't be a problem in the Philippines