I averaged 40 miles per gallon on the highway in a small front-wheel-drive sedan equipped with a 1.4-liter four-cylinder gasoline engine.

I would’ve averaged 42 mpg, or better. But traffic on westbound Interstate 66 was bollixed by highway construction. I sat there in the unusual spring heat along with hundreds of other motorists — engines running and ventilation systems struggling to provide cool air and filter exhaust fumes spewing from adjacent vehicles.

It would have been an ordinary drive in an ordinary economy car, except there wasn’t much ordinary about the 2011 Chevrolet Eco sedan in my possession.

Let me put that statement in context.

Chevrolet is one of the core surviving divisions of General Motors, a company that went through bankruptcy reorganization in 2009, partly because it never took economy cars seriously.

GM’s offerings in the economy segment had been drafted from European and Asian subsidiaries — the hapless Chevette and lackluster Chevrolet Prizm/Geo are examples. Or the company’s price leaders were cobbled together under duress to meet federal fuel-economy mandates that did not count import brands in the government’s tortured, sales-weighted accounting of compliance with mileage standards.

Thus came from GM a less-than-notable class of motorized “C” students — the Chevrolet Cavalier and Cobalt. Both received passing grades but posed no threat to the top of the class — the Toyota Corolla, Honda Civic and Nissan Sentra.

That is why the new Chevrolet Cruze Eco sedan is astounding. It beats all three Japanese rivals in fuel economy. It trumps them in exterior and interior styling. It easily matches them in overall craftsmanship — fit, finish and the quality of interior materials. It also meets them in on-road performance — acceleration and handling. It arguably beats them in safety and utility.

In fairness to the GM administrators who were crushed and scattered under the weight of the recent recession and its attendant corporate bankruptcy, the Cruze Eco and its siblings began development during their executive reign. But they had waited too long to start doing things right. Time and money ran out.

But their replacements in the executive hierarchy of the reorganized GM should be credited for going forward with a good idea — a small, well-designed, highly functional and likable automobile that, at the moment, does not earn the kind of money traditionally brought in by gas-thirsty trucks and sport-utility vehicles — but that probably will do GM greater good in the long run.

Look at the Cruze Eco sedan.

It’s actually attractive. The body flows while simultaneously displaying muscularity. Oh, how I wish my late friend and mentor, Jerry Flint, were alive to see this! Jerry, a longtime automotive columnist for Forbes magazine, routinely bemoaned the boring designs of GM’s economy cars.

“It’s like GM believes lower-income people have no appreciation for any beauty, or for any color other than gray,” Jerry once told me, commenting on the interiors of GM’s economy cars. “It’s as if they think: Yes, it’s boring. It’s an economy car, damn it! You want something better? Buy a truck!”

Ah, Jerry, you would’ve been pleasantly surprised by my Cruze Eco’s well-blended cloth-paneled red-and-black interior — an interior designed as if GM actually cared.

That thoughtfulness is also evident in the car’s engineering. The lower front grille air vent closes at higher speeds (reminiscent of the new Ford Focus) to help increase aerodynamic efficiency. The standard 17-inch-diameter tires are made for lower rolling resistance, which reduces tire-road friction and in that way increases fuel economy.

Personally, I’d be happier with those tire had GM also equipped the Cruze Eco with disc brakes at all four wheels instead of the old-school arrangement of ventilated front discs and rear drum brakes. But old-school works well enough here.

The car’s 1.4-liter, 16-valve turbocharged in-line four-cylinder engine (138 horsepower, 148 foot-pounds of torque) does a competent job for drivers willing to live within posted speed limits. But with a nearly 10-seconds time to move from 0 to 60 mph, it is not the least bit interesting for motorists who fancy themselves performance drivers.

The point is, finally, GM has a small car worthy of the competition — a no-excuses, stands-on-its-merits automobile. That’s solid progress.