Asphalt & Heavy Products Our subsidiaries manufacture and market a variety of heavy products including performancegrade (PG) asphalt, fuel oil, vacuum tower bottoms, carbon black oil (slurry), roofing flux and zero pen asphalt (pitch). We market these products to highway contractors, government agencies, construction material suppliers, asphalt maintenance companies and other wholesale customers from ... HollyFrontier HollyFrontier Dallas, Texas USA.