TRAVERSE CITY, MI – Apparently you can never be too rich or too thin or have too much torque.

Ford Motor Co. proves it today by announcing at the CAR Management Briefing Seminars here it is increasing the torque output of its all-new 6.7L Power Stroke diesel by 65 lb.-ft. (88 Nm), only a few months after it went on sale.

The power upgrade pegs the V-8 turbodiesel at 800 lb.-ft. (1,085 Nm) of torque and 400 hp, giving it an edge over archival General Motors Co.’s 6.6L Duramax V-8, rated at 765 lb.-ft. (1,037 Nm) and 397 hp.

In the never-ending battle for heavy-duty diesel superiority, the Ford Power Stroke initially appeared it would play second fiddle to the Duramax, launching earlier this year with 735 lb.-ft. (997 Nm) of torque and 390 hp.

GM is launching its heavy-duty GMC and Chevrolet pickups now, coincidentally timed with Ford’s announcement that a software upgrade makes the Power Stroke the most-powerful diesel engine ever installed in a pickup.

The game of one-upmanship raises the question: Will GM counter with its own power boost down the road?

The diesel-powered heavy-duty pickup market is relatively small but extremely lucrative for auto makers. Sticker prices easily top $50,000 with options. Ford, GM and Chrysler Group LLC rule the segment, and they wage a titanic battle over market share.

Chrysler competes in the segment with a Cummins 6.7L I-6 turbodiesel that makes 350 hp and 650 lb.-ft. (881 Nm). While less than Ford and GM offerings, the engine’s output still is prodigious, effortlessly pulling a 10,000-lb. (4,536-kg) trailer up a 20% grade in the recent “Diesel Shootout” test by Ward’s editors.

The winner of the Diesel Shootout will be announced Sept. 20. Ward’s editors evaluated the earlier version of the Power Stroke, at 735 lb.-ft. of torque.

Chrysler also touts the fact its I-6 has 30% fewer moving parts than competing V-8s and a well-proven record for durability and low cost of ownership.

But power, especially torque, is crucial to the customers who buy these vehicles specifically to haul heavy loads, from affluent owners of horse trailers and ocean-going boats to commercial fleets.

“These numbers matter because our customers say they do,” says Barb Samardzich, Ford vice president-powertrain engineering.

“The higher torque means fleet operators, such as Florida Power & Light, can plow through deep swamps and get to downed power lines faster and more confidently.

It means that oil and gas crews in the northwest can tow up an 8,000-ft. (2,438-m) grade maintaining a steady speed and using less fuel,” Samardzich says during a speech here.

The power bump is achieved through engine software changes and will not hurt fuel economy.

In fact, fuel economy is expected to improve at least another 2%, making the ’11 F-Series Super Duty 6.7L Power Stroke a full 20% more fuel efficient than the ’10 model, says Chris Brewer, chief engineer of the ’11 Super Duty pickup.

In an earlier interview with Ward’s, Samardzich says Ford was not ready to launch the Super Duty with the upgraded Power Stroke, and that the past several months have been necessary for additional testing and validation.

Increased torque and horsepower means a driver can get to a higher gear faster and hold it longer, which aids fuel economy, Brewer says.

The power improvement also will be evident in situations such as improved passing capability on the highway and when towing a heavy load up a steep grade.

When towing, the increased torque will let the vehicle stay in high gear more often, reducing transmission shifting frequency and keeping engine speed low for better fuel economy and lower noise.

Sometimes when engineers push too hard to increase output, engine noise, vibration and harshness characteristics degrade, and power delivery can become less linear.

However, Ford Chief Engineer Adam Gryglak tells Ward’s the basic Power Stroke architecture is designed to last through decades of changes and power upgrades and this new jump in torque will not negatively impact NVH or power delivery.

Ford will provide the power upgrade free to all current ’11 Super Duty diesel model owners. The process involves reprogramming the powertrain control module software. Customers will receive letters explaining the procedure, which takes about 30 minutes and is done at their local dealership.

The upgrade program applies to about 35,000 trucks and will begin Aug. 31 and continue for 12 months. The program includes unsold vehicles in dealer inventory.

dwinter@wardsauto.com