DHL Express, Plantation, Fla., said it was buying 100 propane-powered light trucks for its fleet.
The trucks will be used in California, Florida, Georgia, Missouri and Texas and on the road by August, DHL said.
The trucks, principally Ford E-250 cargo vans, use a fuel system supplied by Roush CleanTech, Livonia, Mich.
DHL Express also operates propane trucks in Ohio, Tennessee and Louisiana.
Each propane-powered vehicle saves more than 22,587 pounds of CO2 emissions each year, DHL said.