DETROIT – The ’05 Ford Mustang sheds its 1970s-era Fox platform for an all-new, purpose-built architecture to usher in the fifth generation of an American icon, unveiled here at the North American International Auto Show.

The latest pony car grew from a clean sheet of paper and rides on a modern body structure and chassis that can be had for under $20,000.

Ford Motor Co. is confident it has spawned a pair of winners with the choice of the base Mustang with a 202-hp SOHC V-6 engine or the Mustang GT offering up 300 horses with a 24-valve MOD V-8.

The latest iteration will build on 40 years and 8 million sales to date. It holds 40% of the sports-car segment, having run competitors such as the Chevy Camaro and Pontiac Firebird out of the muscle-car market.

’05 Ford Mustang designed to continue 40-year heritage.

Unable to launch the new model in time to celebrate its 40th anniversary April 17, the car will go on sale in the fall. It will be built at the AutoAlliance International Inc. plant in Flat Rock, MI, a joint venture of Ford and Mazda Motor Corp.

“Only Ford can do the Mustang,” says Phil Martens, group vice president-North America product creation.

“With its combination of powerful engines and lots of rear-end torque, it has become an American icon,” says Paul Russell, marketing manager.

“Value for dollar is key,” says Russell. “Fun for dollar is unparalleled.”

Starting from scratch allowed engineers to achieve the desired proportions: long hood, short rear deck, C-scoops in the side, 3-element taillamps and galloping pony in the center of the wide front grille, says Hau Thai-Tang, chief nameplate engineer.

Circular foglamps in the grille immediately distinguish the V-8 from the base model. And the GT gets a raised spoiler on the decklid. While the V-6 Mustang offers a choice of two 10-spoke wheels, the GT’s inch up to 17-in. aluminum wheels in a 5-spoke “mag” style.

The grille extends further at the top for an aggressive tilt forward, opposite of most grilles. Wheel arches come out of side line to add to the look.

The new Mustang is well balanced, whether it has the lighter feel of the 4L V-6 (replacing the 3.8L pushrod engine) or the full might of the 4.6L, all-aluminum 3-valve modular V-8, the first application of this engine. (The F-150 has the 5.4L version of the 3-valve V-8.)

The 3-valve offers more power, torque, refinement and combustion than the outgoing 2-valve, says Thai-Tang. The ’05 has variable camshaft timing, electronic throttle control and faster management controls.

Both engines are mated to the standard 5-speed manual transmission or new, optional 5-speed automatic transmission.

The chassis is comprised of a new front suspension and 3-link solid rear axle to provide the camber and durability sought in a muscle car. A Panhard rod increases control, as does a central torque control arm fastened to the upper front end of the differential. Rigid bushings further enhance steering and handling. The shocks are positioned on the outside of the rear structural rails, near the wheels, similar to the F-150.

Weight distribution is improved with 54% up front, compared with 57% on the current model. The result is better traction, says Thai-Tang.

There is a 35% improvement in torsional stiffness.

The new Mustang is expected to appeal to enthusiasts as well as mainstream buyers of all ages. Stretching the wheelbase by 6 ins. (15 cm) and pushing the wheels forward 5 ins. (13 cm) makes for a roomier interior and the split fold-down rear seat offers a degree of utility. It also shortens the front overhang by 4.6 ins. (12 cm).

The interior can be tailored with optional red leather seats, red door inserts and floor mats, as well as the ability to change the lighting of the clusters on the instrument panel. There are 125 different combinations possible with the configurable cluster from Delphi Corp.

Throw in a 1,000-watt Audiofile sound system, most of which has been moved from the trunk to a new location in the doors. Only the subwoofer continues to eat up trunk space.

It comes with unmatched security in the segment, says Dean Nowicki, Mustang electronics team leader.

In addition to the standard anti-theft system, there is an optional perimeter alarm and ultrasonic intrusion sensor, also supplied by Delphi. An inclination sensor goes off if the vehicle changes elevation – if a wily thief tries to tow it.