Bulk oil is normal brand name oil usually sold to dealerships in 55 gal drums or totes (275 Gal.). Bulk simply means it is not packaged for sale to the average consumer in quarts or gallons. In reality bulk oil would come in a tank truck and be pumped into a tank at the dealership, but many car dealerships get it in drums or totes and call it bulk oil. Bulk oil is the same exact oil that comes in containers (quarts and gallons) less the retail customer packaging. I am sure if you ask any Honda dealer or car dealership that uses bulk oil they will tell you the weight and brand.