Ford's F-150 pickups will soon get an entirely new lineup of V-6 and V-8 gasoline engines that will deliver high power and torque but deliver up to 20 percent better fuel economy than current engines, company executives said on a webcast Wednesday.

The new engines represent "the most extensive powertrain overhaul in the 62-year history of the F-series," declared Doug Scott, Truck Group marketing manager. They include two V-6s and two V-8s, and range from 3.5 to 6.2 liters in displacement. All will be paired with efficient 6-speed automatic transmissions.

"Fuel economy is the Number One unmet need in full-size pickups," Scott said. In surveys of truck users, "70 percent said they wanted better economy, and 30 percent said they'd switch brands to get it."

The new engines were described by engineers Jim Mazuchowski, manager of the V-6 program, and Mike Harrison, who manages Ford's V-8 program. They said all the products use variable valve timing and sophisticated fuel injection systems, and are specially designed for truck duty. contsructed for four valves per cylinder, and other advances. The engines are:

Base 3.7-liter TiVCT (variable valve timing) V-6, rated at 300 horsepower and 275 pounds-feet of torque. It's the latest use of the a 3.7 Duratec car engine that's been beefed up, particularly in its bottom end, for truck use. An F-150 with this engine will be rated to tow as much as 6,100 pounds.

Enhancements for durability include a forged-steel crankshaft, 4-bolt main bearings, cast-iron exhaust manifolds and a die-cast aluminum oil pan, which supports a 10,000-mile interval for oil changes. The design of the cylinder bore and piston rings has been optimized for efficient lubrication.

Ti-VCT's precise and variable control of the intake and exhaust camshafts optimizes performance and fuel economy, Mazuchowski said. Oil is squirted at piston bottoms to enable quick engine warm-up and cooling under hot running, and polished buckets reduce friction, which aids fuel economy. It'll be built at Ford's Cleveland, Ohio, plant.

Optional 5-liter double-overhead-cam TiVCT V-8, with 360 horsepower and 380 pounds-feet and a tow rating of up to 9,800 pounds. Based on a Mustang V-8 introduced earlier, the 5-liter truck version has a new strengthened block, forged steel crank, and new cylinder heads optimized for performance and enhanced cooling, Harrison said.

It has unique intake camshafts, a composite intake manifold and a 10.5 to 1 compression ratio optimized for low-speed torque. An extra oil cooler enhances durability and extends oil-change intervals to 10,000 miles. A new aluminum block is 70 pounds lighter than the 5.4-liter V8's, which aids fuel economy and improves handling. It'll be built in Windsor, Ont.

Premium 6.2-liter two-valve single-overhead-camshaft V-8, with an expanded offering to F-150 SVT Raptor and other specialty applications. Its rating is 411 horsepower and 434 pounds-feet, with a tow rating of 11,300 pounds. It uses two big valves per cylinder, made possible by a large bore and combined with a short stroke for reduced friction losses at high engine speeds.

Because of the large bore size, two spark plugs per cylinder are used to more efficiently burn the fuel-air mixture in the combustion chamber, enabling better fuel economy and increased engine torque, Harrison said. The twin plugs also help the engine maintain a smooth, stable idle.

The 6.2 gasoline V-8 is the standard engine in Ford's revised 2011 SuperDuty pickups. The 6.2 is race-proven, having attained a podium finish in last year's Baja 1,000 off-road race, he noted. It will be built at Ford's Romeo, Mich., engine plant.

Premium 3.5-liter Ti-VCT EcoBoost V-6 is twin turbocharged and has power comparable to a naturally aspirated V-8 and projected class-leading fuel economy, Mazuchowski said. It has variable timing control of both the intake and exhaust camshafts to optimize power, performance and fuel economy. Its fuel economy will be up to 20 percent better than the current 5.4-liter V-8 in the 2010 model year F-150.

The EcoBoost, first introduced in Ford's Taurus, is upgraded for truck use with cast iron exhaust manifolds for heavy-duty operation and durability, improved intake and exhaust camshafts optimized for improved fuel economy and performance, direct-acting mechanical bucket (DAMB) valvetrain with polished buckets to reduce friction and improve fuel economy.

Power and torque are yet to be finalized, but the double-turboed EcoBoost will produce maximum torque between 2,000 and 2,500 rpm, and maximum horsepower should be in the 300 range, Mazuchowski said. Like the 3.7 V-6, the EcoBoost truck V-6 will be built at the Cleveland engine plant.

All the new engines were extensively tested, including a 400-hour full-power and full-torque procedure, to ensure durability and long life, the engineers said. All can burn E85 ethanol-rich fuel.

For the first time, a 6-speed automatic transmission will be standard in the F-150 series, said Scott, the marketing manager. The proven 6R80 transmission has been enhanced to help F-150 customers tow more easily. Ratios are wide for good off-the-line performance and efficient towing. Fifth and 6th gears are overdrive ratios to enable the engine to loaf at highway speeds.

A SelectShift feature includes progressive range select, allowing the operator to limit the number of upper ratios while towing or under heavy load while in Drive, and choosing up- or downshifts in an M-for-manual mode. functions in an M mode, where + and - buttons.

The new powertrains will replace the current 4.6- and 5.4-liter Triton V-8s, which will go out of production at the end of the F-150's 2010 model year. The new powertrains enter production this fall and will go in 2011-model F-150s, which should be at dealers by December.