Cutting back on fuel spend and minimizing environmental impact starts with making fuel efficiency a top priority. Selecting vehicles that achieve the highest fuel economy ratings is beneficial, but one of the most cost-effective and often overlooked methods is simply driving "greener."

Earlier this year, nearly 3,000 corporate fleet drivers from 40 U.S. companies participated in a 10-week program designed to push drivers to operate vehicles in a more efficient manner. The EcoWheels Green Driver Challenge, run by fleet management services provider Wheels Inc., enlisted drivers to pledge to incorporate sustainable driving habits into their daily routines, such as reducing idling time, regularly checking tire pressure, and reducing cargo load.

In less than three months, pharmaceutical company AstraZeneca's fleet reported a CO2 emissions reduction of 367 metric tons. Annually, this amounts to an emissions reduction of more than 1,900 metric tons. With a fleet of more than 5,200 vehicles, AstraZeneca enrolled 503 drivers in the challenge — the most participants of all companies represented.

In addition to producing better driver behavior leading to reduced CO2 emissions, the competition also resulted in a successful reduction in fuel spend.

Seventeen drivers from Deluxe Corporation, a growth engine for small businesses and financial institutions, also participated in the challenge and generated more than $4,000 in fuel savings.

"Our drivers learned to implement simple behavioral changes, such as gradually accelerating, that exponentially impacted the reduction of fuel needed," said Melanie Maile, fleet manager for Deluxe. "We also found [them] to be more attentive to their driving, which can increase driver safety and vehicle longevity."

Utilizing some initiatives from the Green Driver Challenge, Wheels also works with clients to make more fuel-conscious decisions when selecting fleet vehicles.

"The best fuel reduction practices should be tailored to the individual driver and vehicle," said Stratford Dick, senior director of product management and e-commerce strategy at Wheels. "There is no perfect formula for how to reduce fuel spend. Rather, each fleet needs to analyze its needs, resources, and drivers to assess how to make the best fleet selection."

With the goal of achieving a fleet average of 32 mpg by 2012, Indianapolis-based healthcare provider Roche Diagnostics has removed minivans and SUVs from its fleet, replacing them with smaller, more fuel-efficient, four-cylinder vehicles. The company also plans to include more sedan and hybrid vehicle options.

DPR Construction, a commercial building contractor with its corporate office based in Redwood City, Calif., and fleet operated from Maitland, Fla., followed Wheels' recommendations by adding the Ford EcoBoost engine in the 2011 Ford F-150 models and incorporated hybrids for the rest of its fleet. As a result, the DPR fleet will reduce fuel spend by 27 percent by Jan. 1, 2015.

"Reducing fuel expenses is always a priority as a fleet manager, but to accomplish this it is necessary to step back and look at fuel consumption from all angles," said Terri Smith, fleet administrator at DPR. "Implementing better vehicle selection, along with increased awareness of driver behavior practices, allows for long-term improvement and success."