Chevrolet's Sonic Z-Spec concept isn't likely to get lost in the crowd at the Detroit Auto Show.

Chevrolet is betting it can make some big noise with its new small car, the 2012 Sonic.

The new subcompact is the replacement for the unloved Chevrolet Aveo, a car that seemed almost invisible against the Japanese models dominating the small car segment, such as the Honda Fit and Toyota Yaris.

The name is also new and reflects the fact, according to Mark Reuss, General Motors’ president of North American operations, that even GM executives couldn’t decide how to pronounce Aveo.  So, new car, new name.

Set for its formal debut, later today, at the 2011 Detroit Auto Show, Sonic is part of an assault GM is making on various small car segments, from the Korean-made Spark microcar to the new Cruze compact.

Chevrolet replaces the unloved Aveo with the all-new 2012 Sonic.

That’s a big shift from years past when the General considered small cars a waste of time and money, offering them only because it needed their fuel economy numbers to meet the U.S. Corporate Average Fuel Economy standards.  But while that’s still an important motivator, GM is now betting that, with gas likely to push to $4, even $5 a gallon, there will be an emerging market for cars of this size.

Not everyone is quite so sure.  “We like our big cars,” suggests analyst Rebecca Lindland, of IHS Automotive, but she notes that smaller models are nonetheless beginning to gain some traction.

The 2012 Chevrolet Sonic will be offered in hatchback and sedan configurations.

“The small car segment is going through a lot of growth,” contends Margaret Brooks, Chevy marketing director.  In fact, “We believe this will be one of the fastest-growing segment in the American market.

It helps that GM was able to change its business model as it emerged from bankruptcy in 2009 – and won concessions from its union workers.  That allows it to deliver a subcompact that packs in a lot more features than the base econoboxes of decades past.

The stylish, motorcycle-inspired instrument panel is a treat to look at, unlike the chintzy plastic IP of the old Aveo.  Seating is comfortable and the cabin is anything but Spartan.

The Chevy Sonic even pairs a front MacPherson strut suspension with its torsion beam rear, which company officials insist give it a fun-to-drive character.

Buyers have a choice of a base 1.8-liter, naturally-aspirated engine, or a turbocharged, 1.4-liter I4 which, at 138 horsepower is rated 18 hp above Sonic’s crosstown competition, the Ford Fiesta.

Chevy will offer its new entry in both a 4-door and more sporty five-door configuration.

The maker also will show the Chevrolet Z-Spec Concept at the Detroit Auto Show, a eye-popping prototype done up in orange trim and stripes.  No word whether the Z-Spec will be offered for production but considering that younger buyers are demanding the chance to customize their rides, it could be a good possibility.