Ford tries to quiet complaints about diesel engines with new 6.7-liter Power Stroke V8

The first thing you notice about Ford Motor Co.'s new 6.7-liter Power Stroke diesel truck engine is how quiet it is. Standing next to it, you wouldn't know it was a diesel unless someone said so.

The engine debuts early next year in Ford's revamped line of Super Duty pickups. Ford won't talk about horsepower and torque until the Texas State Fair on Sept. 24. But auto writers recently got a preview.

The engine is important. Ford lost customers because of quality problems with the current diesel, which is supplied by International Truck and Engine Corp. Ford produces the new diesel itself.

Ford engineers designed the new Power Stroke with various innovations:

-- Fast-acting piezo fuel injectors supplied by Bosch deliver as many as five shots of fuel per piston stroke. This nearly eliminates the familiar diesel clatter, improves performance and cuts emissions.

-- Aluminum cylinder heads with inward-facing exhaust ports reduce noise.

-- A single, sequential turbocharger with twin impellers delivers performance at low and high engine speeds, reducing turbo lag. The turbocharger, made by Honeywell, is mounted in the "V" between the cylinder heads.

-- A block made of lightweight compact graphite iron helps cut 160 pounds of weight compared with the outgoing 6.4-liter International diesel block. Ford buys the block from Tupy SA, of Brazil.

-- A urea injection system, also from Bosch, helps neutralize emissions of oxides of nitrogen. It's the first Detroit 3 engine to use urea. The chemical will be available at Ford dealerships, truck stops and auto parts stores. The urea tank must be refilled every 7,500 miles.

The engine is designed to last 300,000 miles without major service, says Adam Gryglak, the Power Stroke's lead engineer.

It has been in development for four years. It will be built in Chihuahua, Mexico.

The diesel is one of Ford's most expensive options. The current base F-250 Super Duty starts at $26,275 including delivery. The diesel engine package adds $9,325, which includes a bigger engine cooling system, a stronger transmission and bigger brakes.

Ford says 60 percent of Super Duty F-series pickups are sold with Power Stroke engines, or about 175,000 units last year.

By Richard Truett- Automotive News