FedEx Freight, a provider of regional and interregional less-thantruckload services,will be one of the first major truckers to make a big investment in tractors equipped with "green" engines—engines that comply with Environmental Protection Agency (EPA) emissions rules imposed last year. FedEx Freight says it expects to add a total of 836 new tractors powered by the green engines to its fleet of approximately 9,000 tractors and 25,000 trailers during the carrier's 2004 fiscal year. The new units will replace older equipment as well as increase the overall size of the fleet.

FedEx Freight said it selected an engine manufactured by Cummins Engine because of its quality and compliance with current EPA requirements. According to Cummins, its heavy-duty ISX engine was the first certified to be compliant with the EPA standard, which took effect last October.

Many carri ers have been reluctant to purchase tractors with the new engines , citing concerns that opera ting costs would rise, fuel efficiency would fall and that the new engines would wear out faster than earlier models did.