Reform school for Sonata, Hyundai’s enfant terrible

Pity the second act. Want to follow Led Zeppelin on stage? Ted Williams into the batter’s box? Sebastian Vettel out of the pits?

That is the predicament of Hyundai's new Sonata. The referent-blurring model that debuted in 2006 brought the company a new level of attention and credibility with its so-called "fluidic sculpture", and the car beneath the expressive sheet metal was just as solid.

This puts Hyundai in a jam. How to replace a car that forced the entire mid-size sedan market to step up its styling game? Change for change's sake is rarely a recipe for success.  Onlookers can debate the appeal of the relatively conservative 2015 Sonata introduced at the New York auto show on 16 April, but they won't debate whether the new car will carry the impact of the previous one. Quite simply, it won't.

The question is whether it can capitalise on the current car's gains, or whether would-be customers will be wooed by Nissan Altimas, Volkswagen Passats and other alternatives to Honda Accord/Toyota Camry hegemony.

Hyundai hopes it can, and points to improvements throughout the Sonata that make it a better car in every quantifiable way. "It isn't just one thing," observed Hyundai president and chief executive Dave Zuchowski, "it is the cumulative effect of everything."

There is a laundry list of indisputable improvements to the car, with increased use of high-strength steel – now comprising more than half the steel in the car – more structural adhesive and dual-member main structures in the unibody's frame that is a Jaguar-like 41% stiffer when resisting twisting forces.

The drivetrains represent a maturation for Hyundai, as the company's engineers retuned the existing 2.4-litre four-cylinder engine and turbocharged 2-litre four-cylinder to produce less peak horsepower. This makes the engines look worse when judged by their specification sheets, as the standard engine's power drops from 198hp to 185. But the engines will perform better under their drivers' right feet, as they have been tuned to deliver increased torque and power at the low end of the rev range.

In everyday driving, the Sonata should deliver livelier responses at the engine speeds where customers actually drive. Peak horsepower rating for the turbocharged engine drops to 245 from 274 because Hyundai switched to a smaller turbocharger, which the brand says should deliver quicker response at real-life driving speeds.

Now that Hyundai has earned consumer respect and credibility, it doesn't need eye-popping specifications to grab attention. That is a good sign.

But is rolling back the styling’s aggression a similarly shrewd play? There was no downside to the previous Sonata's voluptuousness. Now the car is more upright and uptight. The character line on the side stretches horizontally front to rear, eschewing the upsweep that gave the previous car its athletic, forward-leaning stance. The formerly slippery grille is now as upright and imperious as that of a classic Mercedes-Benz, contributing to a curious stodginess.

Peter Schreyer, famed for his contributions to the design of the original Audi TT, masterminded a design revolution at Kia, Hyundai’s corporate sister brand, but he was promoted to a corporate board position in 2013. Lacking Schreyer’s direct imprimatur may or may not have affected the outcome of the new Sonata, but the designer is not moved by whispers of a creeping conservativism.

"This car is a bit more about attention to proportion," he said. "I quite like that."

If the Sonata's new act doesn't quite measure up, at least a design superstar is within close reach to dig back into a bag of proven tricks.