According to a study by Allied Business Intelligence, automotive fuel cells will compose nearly 4 percent of the market, or 608,000 vehicles, by 2010. Of these, 80 percent will be Proton Exchange Membrane (PEM) cells. Fuel cell numbers will reach tens of thousands by 2003 to 2004. One of the major obstacles in the way of fuel cells is bringing down the cost with manufacturing capacity starting at 100,000 units. Currently, none of the fuel cell developers have the production capacity according to ABI. It predicts mass production to be reached by the end of the decade, which will make fuel cells competitive with internal combustion engines.