The rising cost of fuel is hitting taxpayers in a way they probably don't think about: transporting President Bush.

Almost every vehicle Bush uses is custom-made to add security and communications capabilities, and the heavier weight further drives up gas and jet fuel costs. The White House declines to discuss travel costs related to the presidential entourage.

Bush is one of the most-traveled presidents. So far this year, he has made more than 75 domestic and foreign trips. The typical presidential motorcade, whether in Washington or overseas, has well over a dozen vehicles, including Bush's limousine and an identical limo put in as a decoy.

Starting with his inauguration in January, Bush began riding in new 2006 Cadillac DTS limos. The full-sized luxury sedan version, available to the public, has an 18-gallon tank that would cost about $47 to fill at a $2.61-a-gallon rate. (White House vehicles are fueled at a special facility, and the price paid per gallon is not released.) Cadillac spokesman Kevin Smith said the Cadillac DTS sedan gets 18 mpg in the city, 27 on the highway.

The vehicle Bush uses is a much different version -- with different gas mileage. An outside company customizes the DTS for presidential use by "stretching" it to limo length, adding bulletproof glass and heavy armor -- making it significantly heavier and less fuel-efficient, Smith said.

The same thing for the Chevrolet Suburbans that are sometimes used as limo substitutes. The mass-marketed 2005 K1500 Suburban would cost nearly $81 to fill up with its large 31-gallon tank. It gets 15 mpg in the city, 19 on the highway, according to Bush's model of the Suburban is custom-fitted with extra gear that would reduce the gas mileage.

Bush most often flies on a Boeing 747-200B laden with, among other things, an anti-missile system. Fuel costs for the largest plane in the Air Force One fleet have gone up dramatically -- from $3,974 an hour in fiscal 2004 to $6,029 an hour now, according to the Air Force.

-- Associated Press

President Bush's customized Cadillac DTS limo is heavier and less fuel-efficient than regular DTS sedans.Air Force One fuel costs are $6,029 an hour, up about $2,000 from fiscal 2004, the Air Force says.The president's helicopter lifts off from the White House lawn, a rising cost borne by taxpayers.