There's room for debate on this aspect of recycling, but many recycling processes require less energy than it would take to manufacture the same item brand-new. Manufacturing plastic is very inexpensive, and some plastic goods can be difficult to recycle efficiently. In those cases, the recycling process probably takes more energy. It can also be difficult to weigh all the energy costs along the entire chain of production. Recycling steel certainly uses less energy than the entire process of mining iron ore, refining it and forging new steel. Some contend that the fleet of recycling trucks collecting plastic and paper door to door every week in cities across the United States tips the balance of energy out of recycling's favor. Energy use is a factor weighed on a case-by-case basis.