The number of '04 car models subject to the federal “gas-guzzler tax” is down slightly compared with the previous model year, says the Environmental Protection Agency.

The EPA's '04-model fuel-economy guide shows 34 nameplates are subject to the one-time tax, which ranges from $1,000 to $7,700. Factor in variants of these vehicles and the number of guzzlers grows to 47.

But that's two fewer than earned the ignominious label in 2003.The '03 total marked a significant jump over '02, when guzzlers numbered 35.

The EPA hangs the guzzler tag on cars that fail to achieve 22.5 mpg Light trucks are exempt.

Not surprisingly, an exotic takes the booby prize for worst fuel economy. The Lamborghini L-147/148 Murcielago rates 9 mpg in the city and 13 mpg on the highway, and its owner typically has to pony up an estimated $2,400 annually for fuel.

Meanwhile, Toyota Motor Corp.'s new Prius earns a tie for first place with Honda Motor Co. Ltd.'s Insight — the EPA's top-ranked gas miser since its introduction as an '00 model. With a rating of 60 mpg in city driving, the Prius manages the dead heat despite a redesign that moved it up from compact to midsize.

The brand that fares worst in the current EPA ratings is Mercedes-Benz. Its marque is found on 20 guzzler models. But, says a spokesman for the auto maker: “We aren't talking about a lot of vehicles here.”

Each of the brand's AMG-badged products is guzzler-grade, but none sell more than 1,200 units annually, he says, adding fuel costs rank low on the priority lists of many Mercedes buyers.