General Motors Corp.’s newest hydrogen-powered fuel cell test car wouldn’t be confused with something that George Jetson might drive and with good reason.

The HydroGen3 is meant to resemble an average four-cylinder minivan. It’s based on the four-door, seven-seat Opel Zafira minivan sold in Europe, a bit smaller than the Chevy Astro.

Inside, the only thing that sets it apart from a conventional vehicle is the driver’s console, where there are forward and reverse arrow buttons where the shifter would be. One other change: Instead of a tachometer, there is a kilowatt meter indicating the surge of electricity to the engine.

The biggest difference is under the hood, where the guts have been torn out and replaced by fuel cell stacks, a cooling system, air compressors, hydrogen fuel tanks and lots of computers.

In fact, everything on board, including the four-speed automatic transmission, is computer-controlled. After the startup and the humming of the air compressors pumping up, the driver only needs to push the reverse arrow and step on the “gas.” The parking brake disengages and the car backs up.

It’s a far smoother ride than in a gasoline-powered car a bit like a souped-up golf cart. While slightly underpowered, it accelerates and decelerates without any of the usual lurching associated with a standard engine and gearbox. Even the electric humming sound is programmed in; if it weren’t, there would be complete silence.

Pulling into traffic on Lomita Boulevard in Torrance, there is a slight lag in accelerating and a heavy feel toward the back. Still, the HydroGen3 can reach 99 miles per hour (an engineer notes that power on the prototype has been tuned down).

Its fuel tanks hold 7 pounds of hydrogen, costing $15 to fill and providing a range of about 250 miles, the most of any working fuel cell car. I try not to think about the tanks, which are pressurized at 10,000 pounds per square inch.

They are under the seat.