To say the least, Transportation Secretary Rodney E. Slater was surprised.

He had come here Tuesday to praise General Motors Corp. and Ford Motor Co. for the progress they've made in developing mid-size family sedans that can run 80 miles on a gallon of fuel.

He was stunned when GM Vice Chairman Harry Pearce unveiled a prototype that gets the equivalent of 108 mpg.

"They told me to expect something extra," Slater said later. "But I thought they meant they'd have something that gets a little better than 80 mpg. But they've seen us, and raised us one with this announcement," he said of GM's surprise presentation of its solid-storage-system, hydrogen fuel-cell Precept sedan.

GM also presented an 80-mpg, hybrid diesel/electric Precept car; and Ford displayed a similarly designed, 80-mpg Prodigy sedan here at the 2000 North American International Auto Show.

Both cars were developed under the Clinton Administration's seven-year-old Partnership for a New Generation of Vehicles (PNGV) program, which combines government and private industry resources in the pursuit of super-high-mileage family cars that offer the same safety, reliability and performance of conventional cars.

So far, the program has consumed $1.4 billion in industry and government money, with about one-third of that coming from the federal government.

The U.S. hybrid/diesel cars will be ready for production by 2003. But similar models made by Toyota Motor Corp. and Honda Motor Co. already are going to market. Toyota this year is introducing its compact gas/electric Prius. Honda has begun selling its smaller, gas/electric Insight.

The U.S. companies say they've been asked to meet a tougher mandate than the Japanese -- to build high-mileage mid-size family sedans, such as the Ford Taurus, capable of safely carrying five to six people and their cargo, while getting 80 mpg.

But the skepticism that greeted the 1993 start of th Clinton Administration's high-mileage program was absent among U.S. auto executives Tuesday.

"Quite frankly, a lot of us doubted that this partnership would work," said GM's Pearce. "But it has worked extremely well," he said.

High-mileage hydrogen fuel-cell cars, which convert hydrogen to electric power via a chemical reaction, realistically will not be ready for market, at least in any meaningful numbers, until 2010, According to auto industry analysts at J.D. Power and Associates in Agoura Hills, Calif.

* Rosalyn G. Millman, acting administrator of the National Highway Traffic Safety Administration, said her agency is developing a rollover rating system for cars and trucks. The labeling system would give new-vehicle shoppers goevernment estimates of the probability of rollover for specific vehicles.

* Perhaps anticipating NHTSA' intentions, Ford Motor Co. announced that it will build 2001-model sport-utiity-vehicles with ceiling air bags that are designed to deploy when sensors detect an imminent rollover.

* It had to happen in a new-vehicle market where 48 percent of the sales are trucks. Germany's Volkswagen AG unveiled its concept Advanced Activity Vehicle at the auo show here. It is a combination pickup truck and roadster, similar to Chevrolet's concept SSR pickup unveiled earlier this week.

* GM has halted production of its battery-powered, EV1 cars, most of which are being leased on the West Coast. Chalk another one up to batteries that fail to give motorists the equivalent miles per tankful of gasoline. The average gasoline-fueled car can run about 300 miles before refueling. The very best of the battery-powered cars, which often means the smallest vehicles with the most expensive batteries, run about 120 miles before recharging. Honda last year also decided to stop producing battery-powered electrics.

* Ready for yet another sexy Jaguar? Ford Motor Co., which owns Jaguar, is showing the concept F-Type Jaguar at the Detroit auto show. It's a sinewy roadster, which can be built with the 240-horsepower V6 currently installed in the S-Type Jaguars, or with a 300-horsepower supercharged version of that engine.

* What gives? GM this year is grouping all of its nameplates under the GM banner at the Detroit show. Ford, for the second year in a row, is doing the same thing. (This year, Ford also has added the Th!NK battery-powered city cars to its lineup.) But at DaimlerChrysler AG, the company that boasts the "merger of equals" (DaimlerBenz AG and Chrysler Corp.), things look more like separate, and not quite equal. All of the Chrysler and Dodge products are being shown on one side of the Detroit auto show floor. Everything labeled Mercedes-Benz is being shown on the exotic foreign nameplate side of the floor. Hmmm. Upstairs, downstairs?