NEW YORK – Mazda caps a whirlwind 24 months of product launches today with the unveiling of the new Mazda3 small car, the auto maker’s highest-volume model worldwide.

Shown to the media in a number of small rollouts around the world, the new model makes its public debut on the Internet at 9 p.m. EDT tonight through a tie-in with Microsoft’s Xbox Live.

In the past two years, Mazda has begun proliferating its Skyactiv high-mileage powertrain technology across its product line, turned its all-new CX-5 cross/utility vehicle into one of its most popular vehicles worldwide and launched sales of its heavily revamped Mazda6 flagship to early success.

But the Mazda3 model accounts for a third of the Japanese auto maker’s global sales, 40% of volume in the U.S. and half of deliveries in Canada, “so clearly, it’s vitally important we get it right,” notes Tim Barnes, director-product planning for Mazda in the U.S.

The car rolled out to the media today is the 5-door version, but the auto maker plans to show off the sedan version, which accounts for 65% or so of U.S. Mazda3 sales, over the next few weeks.

The new model is expected to go on sale in September in the U.S., one of the first global markets to get the car.

Initial supply will come from Japan, but production is targeted to get under way at Mazda’s new Mexican assembly plant in late first-quarter 2014 to supplement supply to U.S. dealers. The Mexican operation ultimately also will produce the Mazda2 and a derivative of that model for Toyota.

The restyled hatchback features Mazda’s new KODO design language, which translates as “Soul of Motion.” That theme of speed and tension is carried out in the new Mazda3’s long hood that leads into a rearward-leaning A-pillar, which slopes dramatically toward the car’s tail. Bulging front fenders, a design technique seen on the Mazda6 and CX-5 as well, and strong shoulder lines add to the Mazda3’s muscular look.

Wheelbase has been stretched 2.4 ins. (6.1 cm) to 106.3 ins. (270.0 cm), and the car measures 175.6 ins. (446.0 cm) in overall length, 1.8 ins. (2.5 cm) shorter than the outgoing model. Drag coefficient is rated at 0.275 and 0.255 for the 5-door and sedan, respectively, if equipped with Mazda’s i-ELOOP capacitor-based electrical-energy storage system and an active grille shutter.

Weight has been trimmed by about 220 lbs. (100 kg), executives say.

The car will debut with a choice of 2.0L 155-hp or 2.5L 184-hp engines, both promised to offer class-leading fuel economy, though Mazda is not ready to disclose expected mileage ratings. The bigger engine also will be offered with the auto maker’s i-ELOOP.

Gearbox choices include either a 6-speed manual or automatic.

The C-segment model also will get Mazda’s new Skyactiv diesel in some markets, including Europe, but executives here say they will wait to gauge interest before considering whether to offer that engine in the U.S. The diesel will debut later this year in the Mazda6 and is expected to make its way into the CX-5 as well.

In Japan, the Mazda3 will be available as a hybrid, employing a powertrain developed in collaboration with Toyota. The hybrid is not a priority for the U.S. at the moment, where Mazda North America President Jim O’Sullivan says he wants to keep the lineup simple for dealers.

“The hybrid is great” but has limited appeal, he says. “With the (fuel-efficient) Skyactiv technology…we will cover everyone in the market.”

There won’t be a Mazdaspeed performance version of the car at launch, and officials won’t say whether such a model is in the works, though that would appear likely.

The new Mazda3 will be available with the auto maker’s complete i-ACTIVSENSE suite of safety technologies, making it the only car in its class to offer such a wide array of collision-avoidance features.

Included in the list are high-beam control, blindspot monitoring, lane-departure warning, forward-obstruction warning, radar cruise control and smart city brake support, which can provide braking assist at speeds up to 19 mph (31 km/h).

Inside, the Mazda3 features a strikingly large center gauge package and an optional pop-up head-up display Mazda calls Active Driving Display, also a first for the segment.

The navigation touchscreen is fixed atop the instrument panel, rather than packaged within. That, says Derek Jenkins, director-design, allowed for a slimmer dashboard that provides a cleaner look and added front-passenger room.

Pricing won’t be announced for several weeks, but executives say the new model will be positioned in the heart of the C-segment, meaning it won’t be the least expensive in its class. Notes O’Sullivan: The auto maker’s pricing philosophy is to be an “alternative to premium.”

Marketing is expected to kick into full gear sometime after launch, following the pattern of the Mazda6, which has been on sale in the U.S. for several months but is just now beginning to appear in advertising.

Sales in the U.S. are targeted to exceed 120,000 units annually, O’Sullivan says, though he does not put a firm number on it. The auto maker’s overall goal is to sell 300,000 vehicles in the U.S. this year.

“It will depend on acceptance and availability,” he tells WardsAuto here, noting the auto maker is straining to meet demand for the Mazda6 and CX-5 in the U.S. How many Mazda3s the U.S. gets may depend on demand elsewhere, he adds, pointing to the uncertainty over the European car market this year and whether it will return to form in 2014.

“We’ll track better than we did with the previous generation,” O’Sullivan says of Mazda3 U.S. sales volumes. “(And) I think we’ll be OK in meeting demand. But it’s a huge opportunity to grow our business.”

The public unveiling of the car, which is being staged from a warehouse in Manhattan’s Chelsea neighborhood and features a live concert from Canadian indie band Metric, will be streamed around the world for viewing via the Microsoft gaming console.

The New York event is the culmination of a daylong global media rollout of the car that began in Melbourne and moved through St. Petersburg, Istanbul and London on its way here.

The auto maker has been promoting the event for a week on social-media sites such as Facebook, Twitter, Instagram and Google.

About 320 people are expected to be in attendance, including VIP customers invited by local dealers, and Mazda officials say there are more than 40 million Xbox Live subscribers in the U.S. alone who will have access to the event.

dzoia@wardsauto.com