In a Wall Street Journal op-ed co-authored with the Environmental Defense Fund’s Fred Krupp, Nooyi writes that it’s time to enact harsher regulations for delivery fleet emissions. “We see an enormous opportunity on the horizon,” the pair wrote. “Trucks are the engines of the nation’s economy.” Krupp and Nooyi call for “a comprehensive approach to fleet efficiency” without offering many specifics. This call comes on the heels of the Obama Administration’s proposal for increased fuel-economy and greenhouse-gas standards for trucks.

In the op-ed, Nooyi highlighted PepsiCo’s efforts to reduce its delivery fleet emissions. The beverage and snack giant apparently lowered its diesel fuel usage by 23% between 2008 and 2014 Frito-Lay North America, all while net revenue climbed to $14.5 billion from $12.5 billion. That’s thanks in (small) part to its fleet of 267 electric trucks, which is actually one of the largest in the U.S. But it’s worth remembering that PepsiCo operates 35,000 vehicles in the U.S. The WSJ piece does not mention PepsiCo’s total emissions, but the company’s most recent Global Reporting Initiative (GRI) report states that PepsiCo’s total emissions was 5,781,000 metric tonnes in 2013.

PepsiCo operates 267 electric-powered vehicles, 272 hybrid diesel-electric trucks, 331 compressed natural gas trucks, and 67 hybrid gasoline-electric vans. It also uses 1,300 hybrid electric cars in the U.S. That represents a modest 6.4%, or 2,237 vehicles, of the company’s total American fleet. While Pepsi should be praised for its leadership on the issue, there’s still a lot more work to be done. Since 2010, the company reduced fuel use by 24%, which helped deliver a decrease in 55,000 metric tons of greenhouse gas emissions.

“The reduction in carbon emissions and diesel fuel usage is due to a holistic approach … that includes the use of CNG trucks, hybrids (both gas and diesel), all-electric vehicles, and efficiency programs such as aerodynamics, GPS … and idling reduction programs,” according to a Pepsi spokesperson.

PepsiCo hasn’t always had such a pristine environmental reputation. Back in 2003, The New York Times published a piece reporting that the beverage giant (along with competitor Coca-Cola) had incited protests in India for allegedly diverting water from villages.

So, was Nooyi’s WSJ op-ed a case of greenwashing or an earnest call to action? Well, for one, it screams of a direct attack aimed at competitor Coca-Cola to ramp up its game. At the same time, Pepsi has consistently presented itself as a green company over the years. This particular cause is reportedly close to CEO Indra Nooyi’s heart.

Pepsi is also cutting back on its water consumption. The company reduced its water use by 14 billion liters in 2013, which helped save $15 million.

Nooyi’s WSJ op-ed ends on a rosy note. “The market has embraced these standards; 2014 was a record year for new truck sales because efficient trucks save companies money.

“Now it’s time to build on this solid foundation. Strong new truck fuel-economy standards will keep America moving in the right direction.”