Commercial vehicles are expected to run on diesel fuel through 2040 due to increases in fuel economy, according to new research from IHS Markit.

In 22 years, 66% of new medium and heavy commercial vehicles sold in the U.S. will be fueled by diesel, compared to 80% today. Range and load capacity requirements from long-haul, on-highway trucking will keep diesel relevant in the short- and long-term, while other vehicle types will grow in popularity as technology continues to advance, according to the forecast.

The findings came in Reinventing the Truck, a research report that analyzes the world’s largest trucking markets.

“Understanding the future course of commercial trucking is so important because its impacts will reverberate far beyond just the trucking industry and through a whole host of industries,” said Daniel Evans, vice president of the IHS Markit downstream practice and co-author of the study. “Trucking accounts for half of diesel demand globally, or one-sixth of oil demand, making the future of trucking critically important for the oil industry. A wholistic, system-wide view is needed to see the full picture of this new reality of transportation.”

The report predicts a 15% compound annual growth rate for battery electric vehicles in the U.S. through 2040, as acquisition rates increase for medium-duty trucks. The initial cost disadvantage of BEVs will require adoption from larger truck fleets first, before they can be implemented by smaller fleet owners and operators.