As gas prices zoom closer to $4 a gallon, Coca-Cola Co. and its two largest U.S. bottlers are shifting their fleets to hybrid vehicles.

Atlanta-based Coca-Cola has transitioned about 325 of the 800 cars and SUVs used by its sales representatives to hybrids. It expects to change out 225 more for hybrids by the end of the year.

Charlotte-based Coca-Cola Consolidated, Coke's second-largest U.S. bottler, now has 400 hybrids, accounting for about half of its car fleet.

Atlanta-based Coca-Cola Enterprises, Coke's largest bottler, has about 30 hybrids in its car fleet with plans to add up to 100 more by the end of 2009. CCE also has added 140 diesel-electric hybrid delivery trucks.

Coca-Cola started studying hybrids for its sales fleet in late 2006, said Bruce Karas, director of sustainability, environment and safety for Coca-Cola North America.

Coke wanted to add hybrids as part of its environmental initiatives, Karas said. Cost savings also were a driver, he said.

At the time Coke proposed shifting the fleet to hybrids, gas was $2.60 to $2.70 a gallon. U.S. gas prices are now averaging about $3.60 per gallon.

"If you look at the price of fuel now, it's going up," Karas said. "The whole picture is continually getting better in terms of the financial benefits of going to a hybrid."

Coke has added four hybrid models to its fleet — the Toyota Prius and the hybrid versions of the Toyota Camry, Toyota Highlander and Ford Escape.

Coke estimates the hybrid sedans are saving it about $1,100 a year per vehicle compared to the non-hybrid sedans. The hybrid SUVs are saving it $800 a year per vehicle compared to a non-hybrid SUV.

The savings vary depending on the type of routes driven by the Coke sales reps, Karas said. Hybrids get their best savings in stop-and-go traffic because the electric motor helps most with initial acceleration.

"One of the things we're learning is you have to think about the kind of driving you're doing," Karas said. "If you're doing a route and you're out in the West where it's all expressway driving, your fuel savings are not as big as if you're doing city driving."

Coca-Cola Consolidated began its transition to hybrids four or five years ago, said company spokesman Lauren Steele. The Charlotte-based bottler continues to add more hybrids as leases come up, he said.

The hybrids have not completely insulated Coca-Cola Consolidated from high fuel prices, Steele said. The company uses the Prius, which has a rating of 46 miles per gallon combined for city and highway driving.

"By using hybrid vehicles, we're mitigating to a degree the increases in fuel costs, but fuel costs are still killing us," Steele said.

Coca-Cola Enterprises also has started replacing its fleet cars with hybrids, said CCE spokesman Fred Roselli. It has about 30 hybrid Priuses, Camrys or Saturn Vues in its fleet of 8,200 cars and plans to add up to 100 more by the end of next year.

CCE also is adding hybrids to its fleet of 20,000 delivery trucks.

CCE started last year with a fleet of 20 diesel-electric hybrids and bought 120 more earlier this year. In tests, CCE hybrid trucks cut both emissions and fuel consumption by about a third.

"Most of our efforts around the hybrids are with our trucks," Roselli said. "We feel that's where we can make the biggest impact."

Coke and its bottlers will continue to look at ways to get more hybrids into their fleets, Karas said. Coca-Cola Co. hopes to have its 800 sales rep cars all converted to hybrids by the end of 2009.

Aside from the fuel savings, the vehicles also provide Coke with a visible way to show customers it has a broader environmental plan, Karas said. Many of Coke's environmental, or sustainability, initiatives take place behind the scenes at the plants.

"If we've made a commitment where we're using a hybrid vehicle, it gives us an entry into a discussion about sustainability," Karas said.