The mighty have finally fallen. Full-size pickup trucks, for many years the best-selling vehicles in the U.S., have tumbled in popularity since the steep run-up in gasoline prices.
As consumers switch to fuel-saving automobiles, the sales decline since last year is 23 percent for personal-use pickups, according to one estimate.

Those who can trade them are taking a financial bath, and there are reports of dealers refusing to take them in on trade because their lots are full of unsold new and used trucks.

This, plus the slump in even thirstier truck-based sport-utility vehicles, is causing fundamental changes in production and product planning by auto and truck builders - developments that have been widely reported in the general media. The price of crude oil on commodities markets fell considerably in late summer and so did gasoline prices, but not enough to reverse those sales trends. And gasoline prices of $4 to $5 per gallon probably won't soon fade from people's memories.

Or will they? Dodge Truck marketers report that pickup sales rose in July and climbed even more in August. "Contrary to some reports, the truck segment is still alive," and accounts for 11 percent of total car and truck sales in North America, says Mark Seguin, launch manager for the redesigned 2009 Ram pickups. Previous busts in the automotive business have been followed by booms, and if the next upswing isn't as great, he and others remain optimistic.

In the meantime, fleets and individual tradesmen still need work-truck versions of light-duty pickups, and here sales are not off so much. That same industrywide estimate, from Toyota Motor Sales USA, says retail sales of work-type pickups are down by 11 percent and fleet sales are down only 2 percent. Fleets tend to buy two-door regular cab pickups, but most other customers select four-door extended or crew-cab models that expand their trucks' ability to haul people as well as cargo.

And several builders have made their light trucks more usable for work. "Cargo management" options with bed extenders, rails, bulkheads and tie-down cleats allow more extensive securement of loads. Storage compartments built into bed sides allow stowage of tools and materials that previously had to be thrown in the bed or the cab, or placed in aftermarket boxes. Rear seats that fold up or down offer flat floors for carrying tools and supplies inside the cab and out of the weather, and without having to put some kind of shell or cover on the bed.

Fuel economy has become more important. Most manufacturers with operations in the U.S. say they have modified their powertrain products so they use less fuel, and more work is being done. They're developing small-displacement diesels for Class 1 light trucks, and the first of these are about a year away. Ford is readying a turbocharged gasoline engine as well as a diesel; Dodge, General Motors and Toyota also have smaller diesels coming. The first "strong" gasoline-electric hybrids in pickups from GM are due out in early calendar 2009, and from Dodge sometime in the 2010 model year.

Cummins is developing the small diesels for Chrysler, Toyota and others. Enthusiasts think the upcoming direct-injection diesels will make them as popular as those in European cars and light trucks. But they tend to forget that while diesels burn less fuel, the fuel itself has long been subsidized in Europe and costs less than gasoline. Here, for the past three years diesel has cost considerably more, and that's not likely to change. And meeting 2010 exhaust emissions limits will be costly. One exception is Dodge, with its Cummins Turbo Diesel that's already 2010-legal.

Early this year General Motors began advertising its class-leading EPA economy ratings, which are as high as 20 mpg highway for some V-8-powered 1500-series half-ton pickups. Hybrid-drive systems now available in GM's SUVs claim 21 to 22 mpg in the city. And recently, GM engineers and planners have cobbled together a package of features they call XFE, for extra fuel economy.

XFE includes the Vortec 5300 aluminum-block V-8, a 6-speed Hydra-matic transmission, a "fast" 3.08 axle ratio, a lower stance, aluminum wheels, low-rolling-resistance tires, and a soft tonneau cover on the bed. XFE production begins in October. The package will first be available in two-wheel-drive Crew Cab 1500s, but might be extended later to other cab styles and perhaps 4x4 models. EPA ratings for XFE pickups is 15 mpg city, 22 highway.

"This was a quick-to-market program," says Carl Hillenbrand, product manager for the Chevrolet Silverado, who notes that GMC's Sierra will also be available with the XFE option. "The fuel economy crunch hit everybody hard, including us. So we asked ourselves, what can we do quickly to ease the pocketbook pain for fuel prices? We put this together fast, starting in late March or early April - so it was about a half a year."

The 6-speed Hydra-Matic, meanwhile, will be mated to all 5.3 V-8s installed in Crew and Extended Cab pickups; it's optional, along with the 5.3, in Regular Cabs. First used with bigger 6- and 6.2-liter V-8s in upscale SUVs, the 6-speed automatic's wide ratio coverage means the 5.3 engine can pull as well with the 3.08 axle ratio as the 4-speed Hydra-Matic does running through a 3.42 rear-end, Hillenbrand says. And because the 6-speed's overdrive keeps engine revs down, fuel economy is as good as a 4.3-liter V-6 with a 4-speed automatic. The V-6/4-speed's remaining advantage is its lower purchase price.

GM, Dodge and Toyota offer V-6 engines in their full-size pickups and at least two V-8s, but Ford dropped the six-cylinder from its half-ton models several years ago and Nissan never offered one in its Titan. For power and fuel economy, Ford compensated last year by applying three valves per cylinder to its 4.6-liter V-8, like its higher-volume 5.4-liter Triton V-8. A two-valve 4.6 remains as the price leader. Nissan is standing pat with its 5.6 V-8, as the Titan has not achieved the volume to support much advanced development.

Nissan's next-generation Titan, due out in the 2011 model year, will be built by Chrysler, using a Dodge Ram chassis with other components being "Nissan-specific." Nissan won't say whose body and powertrain will be employed, but suggests that the new Titan won't be a rebadged Dodge Ram. In return, the agreement between the two builders will have Nissan building a "Chrysler-specific" small car based on the Nissan Versa subcompact.

Nissan meanwhile has formed a Light Commercial Vehicle arm that will market trucks as heavy as Class 5, according to Joe Castelli, who joined Nissan last December to head this group after 23 years at Ford. Light pickups like the Titan are not part of this venture. Nissan builds and sells more than a half-million commercial trucks a year in various world markets, including Mexico, where it is the segment leader, Castelli says. Nissan LCV will display three initial models at the Detroit auto show in January.

Dodge has extensively redesigned its 2009 Ram 1500s with more aggressive exterior styling that's also more aerodynamic; nicer interiors at all trim levels; advanced audio and visual entertainment equipment; more storage bins and cubicles, including covered compartments built into bed sides; and a variety of load securement racks. Standard on all Ram 1500s is a new coil-and-link rear suspension that delivers a smoother ride, especially when the truck is lightly loaded or empty.

Ford has similarly reworked its 2009 F-150 with interior refinements, electronic audio-visual equipment, side steps to help users reach into the high-sided beds, "mid-bed" storage compartments, and a bright-styled Platinum model. Most of these features are aimed at the personal-use market, but Ford also has some unique towing features that make pulling a trailer easier and safer (see product description).

Some observers think both Dodge's and Ford