If we had to sum up the Stinger in a single word, that word would be progress. Because, more than anything else, that's what this four-door grand tourer represents. Progress in quality. Progress in execution. And progress in boldness. Boldness is required to build a car like the Stinger. Though it doesn't quite fit perfectly into any pre-defined segment—it's not really a luxury sedan and it's not completely a sport sedan. Technically, it isn't even a sedan at all—it is a big four-door hatchback GT car with ample power and comfort. And it doesn't embarrass itself in moderately hard driving, either. That's progress.

But beyond the step forward the Stinger represents for the brand, it's also a pleasure to live with. Comfortable, quick, and easy to use, it's an excellent high-velocity road-trip companion. Associate online editor Joseph Capparella might have put it best in his logbook entry: "I love this car. It's a quick, refined, elegant, and stylish grand tourer that cruises effortlessly at high speeds while offering tons of space for both people and cargo."

At our prompting, Kia delivered a set of summer tires for our all-wheel-drive Stinger GT—an OE set of 19-inch Michelin Pilot Sport 4 rubber—which improved its performance in both instrumented testing and daily use. Acceleration remains largely the same, with 60 mph arriving in 4.6 seconds rather than 4.7. The quarter-mile time, at 13.2 seconds, didn't change, but both roadholding (0.89 g versus 0.85) and 70-mph-to-zero braking (170 feet versus 179) were measurably better. Happily, the transmission-overheat warning we experienced almost immediately in our first trip to the track remained at bay this time until our last few runs. The Stinger's on-road performance gives no indication that its transmission is heat sensitive, which leads us to believe this isn't a problem that will crop up in even the most grueling on-road duty cycle.

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