The current market for heavy-duty pickup trucks represents an absolute bonanza for the buying public.

Detroit's three auto makers own this niche, and the one with the freshest product generally has the edge.

Today, all three have just arrived from the orchard, with Chrysler Group LLC's Ram HD launching in late 2009, followed by Ford Motor Co.'s Super Duty last spring and General Motors Co.'s HD pickups this summer.

With a 3-way battle over the years for horsepower and torque supremacy, the auto makers were eager to enter their latest heavy-duty diesel offerings in the first-ever Best Engines Diesel Shootout, conducted by editors from Ward's and our sister publication, Fleet Owner magazine.

Robert Bosch LLC, which supplies common-rail fuel systems and other components for all three trucks, hosted the event July 28 at its test track in Flat Rock, MI. Editors drove up and down 20% grades and ran 0-60 mph (97 km/h) acceleration tests while towing 10,000-lb. (4,536-kg) trailers, provided by GM.

All three diesel entries perform admirably, from the deliciously throaty Cummins 6.7L I-6 in the Ram Laramie 2500 HD to the torque-rich Duramax 6.6L V-8 in the GMC Sierra Denali HD to the amazingly quiet Power Stroke 6.7L V-8 in the Ford F-250 Super Duty Lariat.

Buy any one of them to haul campers or work trailers, and you'll get the job done. Separating the three is difficult because the benchmarking among the auto makers is readily apparent.

In our trailering evaluations, each truck got roughly the same fuel economy (11.6 mpg [20.2 L/100 km]) and each scampered up and down a 20% grade with relative ease.

And all three engines produce amazingly clean exhaust streams, whether at cold start or after an entire day of flogging in intense heat. Like Michigan restaurants and bars, today's new diesel pickups are smoke-free.

But one engine proves better than the others for its lightweight construction, innovative materials, sophisticated aftertreatment, clever packaging and, yes, its ability to squeal the tires while hauling 10,000 lbs.: Ford's Power Stroke V-8.

Ford wins the first-ever Diesel Shootout with a clean-sheet engine designed in Dearborn to replace the Super Duty's powerplant supplied for years by Navistar International Corp.

From the composite oil pan and compacted graphite iron block to the small-frame dual-compressor inboard turbocharger, the new Power Stroke is a magnificent piece of machinery, arguably the finest heavy-duty pickup diesel of the modern era.

Ward's evaluated the first iteration of the new Power Stroke, rated at 735 lb.-ft. (997 Nm), the same engine underhood when the Super Duty went on sale in April.

Meanwhile, GM was launching its new heavy-duty pickups in July with an upgraded Duramax V-8 turbodiesel rated at 765 lb.-ft. (1,037 Nm) of torque.

Even before many GM dealers could receive their first new HD pickups, Ford delivered a crushing blow: Software tweaks enabled the Power Stroke to reach 800 lb.-ft. (1,084 Nm) of torque, a threshold never before reached in the segment.

This announcement came in early August, less than a week after the Diesel Shootout was held and a few days after Ward's editors had chosen the winner. Even at the lower torque rating, the Power Stroke proved victorious. But it was no slam-dunk.

The Cummins I-6 in the Ram gets excellent marks for its bulletproof reliability, lengthy maintenance intervals and rich exhaust tone. The Cummins diesel comes with a high option price of $7,615. But the Ram HD represents the best overall value, considering the Laramie Crew Cab's base price of $42,450 and modest $405 for the optional 6-speed automatic transmission.

The Power Stroke is the most expensive of the three diesel engines, option priced at $7,835, but worth every penny. The Super Duty Crew Cab Lariat carries a base price of $44,095, which includes the standard 6-speed automatic.

The least-expensive engine is GM's Duramax V-8, option priced at $7,195. But factor in the $45,865 base price for the Sierra Denali Crew Cab, and the $1,200 Allison 6-speed automatic, and GMC's heavy-duty truck carries a heavy-duty price tag.

Pricing is important, but our primary mission was to identify which diesel engine could most ably tow a big load.

In 0-60 acceleration runs with 10,000-lb. trailers, the Ram was outgunned badly by its rivals. And as good as the new Power Stroke is, GM's Duramax recorded the fastest times.

The latest Duramax V-8 delivers 11% better fuel efficiency, reducing oxides of nitrogen emissions 63%.

Partly responsible for this gain is the 2,000-bar (30,000-psi) piezo-actuated Bosch common-rail direct-injection system.

Although the Duramax delivers stellar acceleration times at the track, it comes up short in our real-world evaluations on public roads in metro Detroit.

With trailer attached, the Duramax feels and sounds like it needs to work harder than Ford's V-8 to do the same job. Under heavy acceleration, the Duramax sounds downright shrill.

In one back-to-back test, the Duramax needs about 2,000 rpm to tow the trailer up a moderate grade. The Power Stroke in the Super Duty conquers the same grade at the same speed att about 1,300 rpm.

The Ford engine feels like it is barely working at all.

The Diesel Shootout adds another facet to the well-established Ward's 10 Best Engines program, in which editors identify top powertrains based on evaluations during their daily driving cycles.

That method works great for cars, but towing is necessary with diesel pickups. The Bosch test track allowed us to haul camper-like trailers while running acceleration tests in a safe setting.

Bosch, long a pillar in the automotive diesel supply chain, had good reason to host the event. In addition to high-pressure injectors, Ford and GM also use Bosch's Denoxtronic metering system, which works with the urea-based selective catalytic reduction process to cut NOx emissions up to 85%.

If the HD truck product cycles never align quite so neatly in the future, the event might never be held again.

But as long as Detroit's three auto makers continue battling each other in the heavy-duty pickup sector, anything's possible.