I’m waiting for my moment and getting antsy. There’s no break in the flow of cars streaming down the parkway, and I’m tapping my foot on an overused brake pedal, eager to merge into the movement. If this were a crowded subway car, I’d elbow my way in and force the throng to swallow up one more body--but metal, of course, isn’t as forgiving as flesh. Finally, there is a tiny space between two cars, and I take the plunge, a bead of sweat bursting onto my forehead as I wonder whether I’ll have the guns to get up to speed before I get rear-ended. Instead, I nearly rear-end somebody myself: The GS450h roars forward so fast that I almost pop the guy in front of me, who just seconds earlier was traveling 60 miles per hour faster than I was.

So yeah, I guess I should have known that this is one rocket of a car--except it’s a hybrid. Efficient cars aren’t supposed to be powerful. Until now. The first hybrids were weezers designed purely for maximum gas mileage. Then Honda and Toyota started building hybrids that produced good performance, with the fuel economy of, say, a four-cylinder engine. Now the GS450h takes the formula a step further. The instantly available 340 horsepower makes the GS one of the most powerful luxury sedans inside the $60,000 mark. And mileage ratings of 25 mpg in the city, and 28 on the highway, give the GS the fuel economy of a smaller sedan with a modest V-6 engine, or even a four-cylinder. The Toyota Camry with a conventional V-6, for instance, averages slightly lower mileage, yet also produces 26 percent less power. That makes the GS450’s powerplant seem remarkably efficient.

There’s something that doesn’t quite compute about a hybrid engine in such a powerful, luxurious car. It’s like drinking Jack Daniels with Diet Coke. Anybody who really wants to cut down on fuel consumption ought to be willing to live with a bit less power, right? And are people who can afford $60,000 for a car really concerned about saving a few bucks at the pump every year? Well, never mind. Lexus’s job, I suppose, is to make products for people who want to have it all, and can afford to pay for it. Bottomless power with conscionable gas mileage. I suppose there’s a niche for that.

As for the rest of the GS450h, it comes with same bumper-to-bumper refinements found in the GS430, Lexus’s mid-tier luxury sedan. The slick workmanship in the cabin may be the best in the industry, from perfectly spring-loaded lids on storage boxes to supremely comfortable seats. The GS isn’t huge, and large adults might feel cramped in the back seat. One compromise on the hybrid model is truncated trunkroom, since the hybrid battery pack takes up a fair amount of space behind the rear seat. But the interior is sumptuous and cozy, and on the hybrid model the cabin is as quiet as a meditation room. Maybe a hybrid engine is a luxury after all.