DEARBORN, MI – The 50th Anniversary ’15-model Ford Mustang gets modern new sheet metal, but its most important features lie under the skin: an all-new platform with an independent rear suspension and a new, powerful 2.3L Ecoboost 4-cyl. engine.

Ford isn’t saying, but the Mustang’s upgraded, ride-enhancing suspension, which replaces the solid-rear axle in the current model, clears the way for the automaker to spin other models from the muscle car’s chassis.

The addition of a 4-cyl. to the engine lineup – absent from the Mustang since the ’93 model – was made so the car can make a bigger dent in international markets, Ford officials acknowledge. Currently, the Mustang is sold only in a handful of countries outside North America.

The new car, unveiled here today as well as in New York, Barcelona, Shanghai and Sydney, keeps a lot, but not all, of Mustang’s traditional design cues but has a wider track and sits lower to the ground than the current car.

A convertible model is rumored for debut at the North American International Auto Show in January, and a number of high-performance versions are expected to follow the launch of the standard car.

Ford isn’t revealing any sales goals, but international markets will be a big driver in whether the new Mustang is considered a success. It hits U.S. showrooms in fall 2014, then will roll out in Europe in first-half 2015 and in the Asia/Pacific in the second half of the year.

In the U.S., the Mustang will be offered with a base 3.7L V-6 delivering 300 hp and 270 lb.-ft. (366 Nm) of torque. The EcoBoost 2.3L 4-cyl. will mark a step up, at more than 305 hp and better than 300 lb.-ft. (407 Nm) of torque, the automaker says.

Topping the line will be a 5.0L V-8, rated at more than 420 hp and 390 lb.-ft. (529 Nm) of torque. Although a carryover, Ford says it made several improvements to the 5.0L engine, including larger intake and exhaust valves, revised camshafts, stiffer valve springs, a new cylinder head, sinter-forged connecting rods, redesigned pistons and a rebalanced crankshaft for higher-speed operation.

A new intake manifold includes charge-motion control valves to partially close off port flow at lower engine speeds, improving fuel economy.

International markets will offer only the 4-cyl., which is the first Ford engine to get a low-inertia twin-scroll turbocharger, and the V-8.

“We’ll go into the market and see how it will do,” Chief Operating Officer Mark Fields says of the return of the 4-cyl. engine after 20-plus years. “We’ll have the flexibility on production (either way). We think it will appeal to a lot of different folks.”

The pony car also adds a long list of advanced technology to enhance safety and comfort, including blindspot and cross-traffic alert systems and Ford’s SYNC and MyKey features. It also gets pushbutton start, and its 6-speed automatic will have paddle-shift capability. Top speed has been increased to 155 mph (249 km/h).

Design chief J Mays, who will retire from Ford in January, says his team took an airplane-cockpit approach to the interior, which features round analogue gauges and toggle switches to control various systems.

“We spent a lot of time on those analogue gauges,” he admits. “This is an analogue car, not digital.”

Although Ford had international markets in mind from the outset, Mays says the styling was driven completely by the Mustang’s heritage. He notes the car’s low front fender and various “bumps and bulges” on the hood help to comply with pedestrian-safety requirements in Europe, but adds, “That helped create a more powerful look.

“Going global is interesting, but we wanted to design a Mustang first,” he says.

Ford did step away from some long-held Mustang design cues in creating the new-generation car. Gone are the hockey-stick pattern chiseled into the pony car’s doors and the fake gas cap at the rear.

“We couldn’t put every single design cue in,” Mays says. “And I don’t think it’s necessary. We’re walking away from some things we don’t think we need anymore.”

The new model’s grille also shares some resemblance with other Fords, Mays says, noting the injection of global design DNA doesn’t detract from the car’s American-icon leanings.

He says the automaker went through about 15 prototypes before arriving at the final design, each being another step “in the right direction.”

Ford isn’t releasing all the technical details yet, but effort was made to keep weight down. The ’15 model features an aluminum hood, fenders and knuckles for its new independent rear suspension.

However, Frank Davis, executive director-engineering team, tells WardsAuto most of the focus on weight was more about getting the balance right for handling. He says the new model will handle better than the current Boss edition of the car, and Ford also set some development stretch goals by benchmarking the BMW M3 and Porsche 911.

Some changes will be made to the car to accommodate demands in other markets, Davis says. European cars, for example, will get different suspension bushings and electric-power-steering calibrations to fit the market’s penchant for a firmer ride and more precise handling.

Mustang sales, at 71,459 units, are down 7.7% through November, according to WardsAuto data, and the car trails rival Chevrolet Camaro by 4,000 units. Sales peaked at 540,802 units in 1966, and volume hasn’t topped the 100,000 mark since 2007.

Fields says only that the 417,000 units sold in Mustang’s very first year, “is not our volume target with this vehicle,” but he likes the car’s chances for expanding sales globally.

Mustang’s Facebook site has more than 5.5 million followers, half of which are outside the U.S., he notes, adding there are 300 Mustang enthusiasts’ clubs on five continents.

“The Mustang has appeal across the world,” he says. “There’s a lot of opportunity in China, the Asia-Pacific and Europe.”

Adds Mays, “There’s 50 years of pent-up demand (in international markets).”

Production will continue at the Flat Rock, MI, plant with the new model. The inclusion of a more compliant independent rear suspension means the chassis will be more suitable for other vehicles, possibly including a sedan for the Lincoln brand, though Ford won’t comment on plans to expand use of the platform.

General Motors plans to move its next-generation Camaro to its Cadillac ATS/CTS architecture, and Ford likely will be looking for ways to improve the Mustang’s business case by making better use of its chassis as well.

Asked if that’s part of the game plan, Fields says simply, “We’re here to talk about Mustang today.”

dzoia@wardsauto.com