Enterprise Rent-A-Car announced a green marketing strategy this week, STLToday reports. Enterprise has been collecting data and preparing to launch the campaign for the past 18 months.

Enterprise says it has more fuel-efficient vehicles than any other rental car company in the world, with 334,000 vehicles that average at least 28 miles per gallon, including 199,000 that average at least 32 mpg.

The data does not include either corporate-leased fleet vehicles or the additional 300,000 vehicles added to its U.S. fleet in March.

In addition to publicizing data about its fleet, the company has decided to push efforts such as its underwriting the planting of 50 million trees over the next 50 years at a total cost of $50 million dollars into the forefront of Enterprise’s public image.