Decarbonizing Combustion Vehicles: Transportation Energy Institute

S&P Global Mobility1 reports that in July 2021 BEVs represented only 0.42% of vehicles in operation, which left 282 million internal combustion engine vehicles (ICEVs) on the roads in the U.S. By 2030, it is projected there will be 290 million ICEVs in operation. That same year, BEV sales were projected to total nearly 2.8 million units. If LDV sales maintain their historical level of about 16.5 million vehicles per year, this would mean that, even in 2030, consumers will purchase nearly 14 million new ICEVs, and those vehicles can be expected to be on the road in the U.S. for at least fifteen years. Accordingly, large numbers of ICEVs consuming liquid fuels will be on the road in the U.S. for decades to come.

Given the objective to reduce carbon emissions from the transportation sector, waiting for the market to transition to ZEVs without seeking solutions for the dominant powertrain on the roads is a strategy which ignores the substantial reductions which can be achieved in current and future ICEVs. Embracing strategies to reduce carbon emissions from the nearly 300 million ICEVs that will continue to operate in the U.S. for the next several decades is imperative.

Fortunately, total lifecycle, as well as tailpipe, emissions reductions are already being achieved by increasing use of biofuels and reducing the carbon intensity of the fuel mixtures used in ICEVs. Additional near-term steps to reduce the carbon intensity of fuels will play a critical role in limiting the expected increase in cumulative mobile source greenhouse gas (GHG) emissions. ICEV technologies and the associated fuels can continue to be employed over broad and energy-intensive transportation applications while making substantial contributions to near- and long-term GHG emissions reductions. In fact, substantial reductions in GHG emissions from LDVs in the near term can only be achieved by reducing emissions from ICEVs.

Stillwater Associates was engaged by the Transportation Energy Institute to identify and analyze the potential opportunities to expand on this critical GHG-reduction strategy. In this report, we examine the benefits achievable through the decarbonization of the existing on-road U.S. ICEV fleet given the extended timeframe which will be required to transition that fleet to ZEVs.