Market penetration models are presented, illustrating that direct hydrogen fuel cell vehicles could eventually provide industry with substantial return on investment without government subsidy, while at the same time significantly reducing environmental degradation and oil imports. This marker penetration model estimates the likely number of fuel cell vehicles that might be sold in the United States over the next three decades, based on the projected costs of these vehicles and the cost of hydrogen compared to other clean vehicles that might compete for the California zero emission vehicle market. Initial results are shown comparing the marker penetration, societal benefit/cost ratios and return on investment estimates for direct hydrogen fuel cell vehicles compared to fuel cell vehicles with onboard fuel processors including methanol steam reformers and gasoline partial oxidation systems.