NEW YORK (Reuters) -- Tens of thousands of U.S. military vehicles, ships and aircraft are guzzling fuel every day around the world and with the bill rising the Pentagon is trying harder to conserve.
The U.S. military consumed 144.8 million barrels of fuel in 2004, spending $6.7 billion, according to the Defense Energy Support Center.
Last year, it consumed only 128.3 million barrels, but spent $8.8 billion, as the average price per barrel rose by almost 50 percent to more than $68.
For 2006, the energy support center estimates the military will need 130.6 million barrels and pay more than $10 billion for it, at a price of more than $77 per barrel.
"The U.S. Army burned 12 times more fuel per soldier in Iraq than it did in France in 1944 -- nine gallons of fuel per soldier per day in 2004," said Carlton Meyer, a former Marine officer who runs G2mil Quarterly, a Web site on military issues. "Another problem is that truck fuel tankers are easy to identify and destroy by enemy guerrillas."
As oil prices hit a record $70.85 per barrel last year and have hovered around $60 ever since, the Pentagon realized the only way to soften the blow would be to consume less.
"Fuel and upkeep for aircraft... with 1950s era engines and design expose us to soaring fuel prices, increased maintenance and obsolete spare suppliers," said Gen. Michael Moseley, Chief of Staff, U.S. Air Force in testimony to the U.S. Senate Armed Services committee earlier this month.
Fears of shortages after Hurricane Katrina gave the issue new urgency, prompting Deputy Secretary of Defense Gordon England to send a memo last September asking all military departments, defense agencies and employees to conserve fuel.
Amid the measures England suggested were increased training on combat simulators instead of actual war machines and shutting down engines instead of idling.
Two months later, the Pentagon also ordered all defense facilities to cut their energy consumption each year by 2 percent and to increase their use of renewable energy to 7.5 percent of total demand by 2013 and 25 percent by 2025.
Even as the White House repeatedly said the jury was still out on whether industrial emissions caused global warming, the Pentagon ordered facilities to cut greenhouse gas emissions by 30 percent from 1990 levels by 2010.
The biggest gas guzzlers are heavy armored vehicles, such as tanks and humvees, and aircraft, such as the massive B-52 bomber.
They were designed decades ago, when gas prices were not an issue. But they have remained a vital part of combat missions.
A case in point is the Abrams tank, designed in 1979 for rapid assaults across Europe against the Soviet Union.
Its massive armor can survive vicious direct hits and its turbine engine can propel it from zero to 20 miles per hour in seven seconds.
But it weighs 70 tons and consumes 56 gallons an hour at full clip and 10 gallons an hour while idling.
"If we could reduce the amount of fuel we need on the battlefield, that would cut down on the number of trucks that have to travel around carrying fuel and therefore reduce the number of soldiers exposed to harm's way," said Lt. Col. Mike Flanagan, manager of the U.S. Army's program to improve the tank's engine.
Replacing the turbine engine with a more fuel-efficient diesel engine was not feasible, so the Army decided to try to make the existing engine last twice as long and reduce fuel consumption on stationary missions.
Some tanks already have a small generator attached on the back of the turret, while others will get six extra batteries that the crew can run instead of idling the engine.
The Army shares all these improvements with the Marines, who use the Abrams tank and are also researching a hybrid electric engine for use in reconnaissance vehicles.
Meanwhile, the U.S. Navy is looking at future applications of fuel cell technologies, while the Air Force is studying putting more fuel efficient engines on the Vietnam-era B-52 airplane, which remains the Air Force's primary bomber.