Ford's F-150, America's perennial best-selling vehicle and part of a truck line that has claimed sales leadership for 31 years, may well keep that distinction, thanks to an extensive redesign for the 2009 model year. The full-size half-ton pickup, used primarily for personal transportation but also as a work truck, has edgier exterior styling, posher interiors, all V-8 power, and chassis upgrades that Ford says make the truck more capable and useful. The new F-150 in many iterations goes on sale this fall.

Choice is the watchword. The '09 F-150 will have three cab styles, four box lengths and seven trim levels, yielding 35 possible combinations, Ford executives said in an announcement at the Detroit auto show last month. Among the cabs is a Super Crew that's 6 inches longer than the current model, and features a fold-up rear seat that leaves a completely flat floor for secure hauling of bulky boxed items.

Grilles follow the bold theme established by the'08 Super Duty pickups and soon extended to E series vans, and include Ford's now-signature three horizontal bars with side "nostrils." Some are in black and others have chrome trim. Bed lengths range from a traditional 8 feet to a 5.7-foot type that goes with the longer Super Crew cab. A new tailgate is styled to resemble the grilles, with three stamped-in "feature lines" that tie in to the tail lights and curve upward to form an aerodynamic lip at the gate's top. The lip also makes room to stow a tailgate step first introduced on the SuperDuties.

The now venerable two-valve-per-cylinder 4.6-liter Triton V-8 will become the base engine. The 4.6 can also be ordered with three-valve heads, and the three-valve 5.4 V-8 remains the top engine. More efficient combustion enables each to get about 1 mpg more than the current model, and even the base 4.6 gets better economy than the current 4.2-liter V-6, which is being dropped. The base V-8 comes with a 4-speed automatic transmission, and the optional V-8s come with a new 6-speed automatic. All engines meet Low Emission Level II requirements.

Chassis are claimed to be stronger to allow more payload and trailer towing capacity. Trailer Stability Control and an integrated trailer-brake controller are among available equipment. The frame continues to have fully boxed rails joined by crossmembers whose ends run through the rails for great strength, and the '09 frame claims 10 percent greater torsional rigidity than current models. The front suspension has double wishbones, long and short arms, and coil springs over shock absorbers - a smooth-riding design borrowed from the Expedition SUV, but further refined for the F-150.

The rear suspension is a Hotchkiss type with a live axle and leaf springs 2 inches longer than current springs. Shocks remain outboard-mounted (a feature introduced in '04 F-150s) for positive control of wheel movement. An electric-locking differential is used on the FX4 model, and transfer cases on all 4x4s can be either electronically or manually controlled. Four-channel ABS with Roll Stability Control is standard. Wheel-tire choices include 17-inch sizes to enhance off-road ability.

Interiors have new fabrics and real metals that suggest a "built" rather than "designed" look, Ford says. There's more storage space, including a center-console compartment large enough to hold two laptop computers - a nod to the fact that many owners work out of their trucks. Gauges have fresh faces, and switches and buttons are larger for easier use. Navigation systems are optional. Radios have Ford's new Sync hands-free control system plus USB and MP3-player input ports. Sound-deadening materials are progressively employed up the trim-level ladder, and the top-of-the-line Platinum model is said to be quieter inside than a Lexus LS450.

Trim packages start with the base, workaday XL, then ascend to STX, FX4, XLT, Lariat and King Ranch. The apex is a new Platinum package, with extensive "satin chrome" pieces in the grille and on the tailgate, "tuxedo-stitched" and embroidered seat covers on power captain's chairs, ash wood-grain accents and brushed-aluminum elements. All trim levels get new badges that resemble hand-crafted belt buckles, Ford says.