WASHINGTON (CNN) — Walmart is adding 2t and 3t engine additives to all of its 3.5 million vehicles in an effort to boost efficiency and curb emissions.
The move follows a recent study that found gasoline was the leading cause of air pollution in the United States.
Walmart said the new 2t additives would be used to enhance the performance of the engines, as well as in the catalytic converters used in catalytic cracking.
The addition of the additive helps reduce the number of combustion emissions.
Wal-Mart said it had not yet determined which of its vehicles would benefit the most from the change.