How do you update an icon? Carefully. Very carefully. With 50 years of history behind it, the Mustang has a tremendous legacy—and a fair bit of baggage, too. With the most recent reset of the vehicle that invented the ponycar category, Ford engineers had a tough job on their hands: making the latest Mustang both fresh and familiar at the same time.

Now entering its sixth design generation, the Mustang is a tightly defined package. Buyers have come to know exactly what they want over these past five decades, and the designers can't stray too far and disappoint them. So not surprisingly, even though the latest Mustang rides on an all-new S550 platform, the wheelbase is exactly the same as the old S197 chassis at 107.1 inches. The Mustang formula—long hood, short deck, 2+2 seating, space for V-8 power, tires, and brakes—defines the major hard points. To a surprising extent, the Mustang now designs itself.

Of course, the biggest change for the Mustang in 2015 is the new independent rear suspension. After all these years, the traditional live axle has finally been retired, replaced with a new Integral Link system with coil springs and aluminum lower H-arms. The Mustang is now on the same page as the rest of the world in ride and handling quality, finally, but that's not the half of it. With no bulky live axle gobbling up vertical travel in bump, the floorpan could be lowered, increasing the available cabin volume. This, in turn, allowed the stylists to lower the roofline a dramatic 1.6 inches and push back the A-pillar 1.2 inches, lengthening the hood an equal amount. The Mustang's visual essence—the special mix of elements and proportions that make a Mustang look like a Mustang—was enhanced.

While the overall profile is now noticeably sleeker, the changes in the Mustang's exterior details are subtle. Essentially, designers took the current EVOS/One Ford corporate design language, including the trapezoidal grille and other cues, and stretched it over the classic Mustang form. If the design goals were to create a pleasing design that couldn't possibly be mistaken for anything but a) a Ford and b) a Mustang, even in a rainstorm at midnight, mission accomplished.

Today, ponycars are also muscle cars, and engines are key ingredients. So far, three available powerplants have been announced, and each one offers 300 hp or better. Standard is the 3.7L V-6 that was brand-new in 2011. With twin-cams, four-valve heads, and variable cam timing, this piece is rated at 300 hp at 6,500 rpm. The standard V-6 illustrates how spoiled we've all become by current engine technology. Remember when the '79 Mustang V-8 boasted all of 140 hp?

The Mustang GT's standard V-8, the one rodders like to call the Coyote, has been tuned up for 2015. The upgrades include larger intake and exhaust valves, better-flowing cylinder heads and intake manifold, and revised cam lobe profiles. Final output figures are yet to be announced, but Ford engineers assured us that the revamped Coyote will make "significantly better” numbers than the current package, which is rated at 420 hp at 6,500 rpm and 390 lb-ft at 4,250 rpm. Boss and supercharged Shelby engines with even greater power are expected at some point down the road.

Of course, the newest item in the 2015 engine lineup is the 2.3L EcoBoost, a turbocharged, intercooled inline-four with a projected output of more than 305 hp and better than 300 lb-ft of torque. One of the most advanced engines ever produced by Ford, the Mustang EcoBoost features a die-cast aluminum block, integral piston squirters, a balance shaft, direct injection, and a DOHC four-valve head with twin-independent variable camshaft phasers. The twin-scroll turbocharger, a first for Ford in a production automobile, provides quicker torque delivery and reduced throttle lag.

While some may be surprised, this isn't the first turbo four Ford has offered in a Mustang. Hard-core Blue Oval people will recall the '84-86 Mustang SVO, which produced up to 205 hp. Naturally, Ford has advanced its turbocharger expertise a fair distance since then. The EcoBoost delivers a third more power with the same 2.3L displacement, and promises considerably better driveability. Buyers who opt for the EcoBoost can expect to pay a $1,000 premium over the base V-6, but will gain improved fuel economy. EPA mileage ratings, however, have not yet been released.

The V-6 and EcoBoost I4 are both calibrated to run on 87-octane (R+M/2) regular gasoline, while the Coyote V-8 prefers 91-octane premium for best performance. All three engines are offered with the buyer's choice of Getrag six-speed manual gearbox (with standard hill-holding function) or the Ford SelectShift six-speed automatic transmission, which includes steering wheel–mounted paddle shifters as standard. Ford and General Motors are currently working on a joint venture to produce a 10-speed automatic, but the result of that effort is still a few years down the road.

One point that's drawn considerable interest and some skepticism: While the final specifications have not yet been released, Ford sources confidently say the new car will be at least 200 pounds lighter than the current Mustang. How that could be accomplished has a few observers scratching their heads. How can a vehicle cover the same footprint, include additional safety and convenience features, not to mention bigger wheels, tires, and brakes, and still come in 200 pounds under the previous model? (For reference, the 2014 curb weight is 3,618 pounds.) This is a feat that bears watching, and we'll stay tuned. The '15 Mustang arrives in showrooms in the fourth quarter of 2014!