After watching C.A. Dutch Ruppersberger rule the roads for years in a green Ford Expedition, a Godzilla of SUVs, Baltimore County motorists might have a hard time spotting new County Executive James T. Smith Jr., who is bucking the trend among local politicians by opting for a Buick LeSabre, a car that practically screams "sensible."

Among the region's executives, only Anne Arundel County's Janet S. Owens had anything smaller than a sport utility vehicle - a Ford Crown Victoria - until Smith came on the scene.

Harford County's James M. Harkins recently traded his Chevrolet Tahoe for a Chevrolet Trailblazer; Mayor Martin O'Malley, following in Ruppersberger's footsteps, patrols the city in an Expedition; and Howard's James N. Robey, keeping up with the Joneses, ditched the Crown Victoria he had when he first took office in favor of a Ford Explorer.

But that's just not Smith's style. "I'm a sedan-type guy," he said.

Although Smith has kept many of Ruppersberger's appointees, he decided to get rid of the bright green Ford Expedition his predecessor said was necessary so he could roam the county in the midst of the worst blizzards.

Robey ditched the Crown Victoria for an Explorer for the same reason Ruppersberger wanted the Expedition, said Robey's spokeswoman, Victoria Goodman.

"He requested a four-wheel-drive vehicle when the Crown Vic was expected to come off service, which he does use in bad weather to check things out," she said.

"It's really pretty small by SUV standards these days," Goodman added.

Confronted with a snowstorm in his first week in office, Smith hitched a ride in his security officers' car, which has four-wheel-drive.

"It wasn't a problem," he said.

Elise Armacost, who was Ruppersberger's spokeswoman and has the same job for Smith, said her former boss needed the SUV for more than just snow. For him, the Expedition was a mobile office.

"He's a big guy, and he liked to spread out," Armacost said. "As someone who rode with him a lot, I can tell you, when he spreads out all his papers, you could see why he wanted something roomy."

Another factor to consider, Armacost pointed out, is that the executive is accompanied by a corps of drivers/security officers, one of whom is about 6-foot-7 and 270 pounds. The constant presence of others in the car helped persuade Smith to upgrade from his original choice of a Mercury Sable, she said.

Now that Ruppersberger is off to Congress, the county is auctioning his old vehicle. County Budget and Finance Director Fred Homan estimated it will fetch $4,500, unless bidding catches fire when buyers learn of its celebrity past, Armacost said.

"He jokingly said maybe we should sell it at Sotheby's," she said.

Although Smith declined to discuss the comparison, his choice of cars is far more economical and ecologically sound. Not only is the car itself cheaper - his LeSabre, bought used, cost $15,414, and Ruppersberger's Expedition, also used, cost $29,344 in 1998 - but the LeSabre also gets much better gas mileage.

The U.S. Department of Energy estimates that a 1998 Expedition gets 15 miles per gallon based on an average breakdown of city and highway driving. The 2002 LeSabre gets 23 mpg.

In the four years Ruppersberger had the Expedition, he drove 125,908 miles, so if he had been in the more fuel-efficient LeSabre, the county would have saved nearly 3,000 gallons of gas.

The difference would also have resulted in about 37 fewer tons of greenhouse gases being emitted into the atmosphere, according to Department of Energy estimates.

Ruppersberger isn't entirely without eco-credentials. The Sierra Club endorsed him in his congressional bid this fall and praised his efforts to continue and expand Baltimore County's land preservation and anti-sprawl policies. The League of Conservation Voters also worked to defeat his opponent.

And in any case, Rick Kunkel, who ran for the House of Delegates this fall as the county's only Green Party candidate, said Smith's choice is only marginally impressive.

If he were driving a Honda Insight - an electric/gasoline hybrid that gets 56 mpg - then Smith would be on to something, Kunkel said. Better yet, Smith could take the bus, leading by example with a nonpolluting lifestyle while seeing at the same time the challenges faced by his poorer constituents, Kunkel said.

"If I could have my Christmas wish, I really would encourage Mr. Smith to take public transportation to work once a week or once a month, or maybe bicycle to work once a month," Kunkel said. "I think that would really help him to understand the issue of mass transit to really get a true sense of how difficult it is for people who don't have a vehicle to get around."

But with a LeSabre, Smith is, literally and figuratively, putting himself on the same level as his constituents, said Keith Bradsher, author of High and Mighty, a critique of the rise of the SUV in American culture.

In his book, Bradsher, who was The New York Times' Detroit bureau chief for five years and is the paper's Hong Kong bureau chief, quotes from auto industry marketing studies that find SUV buyers tend to be "insecure and vain ... self-centered and self-absorbed."

"The auto industry's own market researchers say that buyers of big SUVs are people who like to be able to look down on others," Bradsher said. "It sounds like the new county executive is more of a man of the people, who likes to be on the level with others."