The 2001 GMC and Chevy heavy-duty pickups take aim at Ford.

General Motors, riding a 1_1/2-year wave of sales success since it redesigned its medium-duty GMC Sierra and Chevy Silverado trucks, hopes to extend this streak into heavy-duty (HD) trucks beginning this fall.

How does it plan to steal the full-size pickup truck sales crown owned by Ford for the past two decades? "By 2001, we'll be the leader in this market because we've made an unprecedented investment to know the customer and then deliver heavy-duty trucks that boast more powerful diesel and gas engines, more capable transmissions and segment-leading tow/haul ratings, creating a new benchmark for full-sized trucks," says Gary White, vehicle line executive.

Similar design. The HD models continue the theme of the current Silverado and Sierra designs, with some design tweaks on front grills and hoods to further differentiate Chevy from GMC. The company plans to add more differentiation in the future, especially since it is striving to make the GMC brand its work truck.

The cab interior of the trucks is similar to that of their respective half-ton models. Brand differentiation is not apparent here: The Chevy and the GMC seem practically identical in appearance. Both brands will offer a choice of regular cab, 4-door extended cab, crew cab and chassis-cab models.

Better powertrain. It is here where GM claims to overtake the competition. Both brands will offer a choice of three engines for 2001: the new Duramax Diesel 6600, the new Vortec 8100 and the standard Vortec 6000.

Because diesel engines power 50% of HD trucks, GM got together with Isuzu to design and build the most powerful diesel in the segment specifically for its 2001 models. GM claims that the new Duramax Diesel 6600 has segment-leading power ratings by delivering 300 hp at 3,100 rpm and 520 lbs. ft. of torque at 1,800 rpm, while setting new benchmarks for controlling diesel noise, vibration and harshness. In fact it's so quiet, GM claims, that people even try to start it when it's already running.

The 6600 is a totally new, 90 degrees, direct-injection, overhead valve (4-cyl.) turbocharged diesel V8 with aluminum high swirl cylinder heads and significantly improved cooling characteristics. Fuel economy is improved by 15 to 20% over previous GM diesels, and the engine has a long targeted operating life of at least 200,000 miles without major component failure.

If it's gas power you want, GM has an all-new big block Vortec 8100 V8, which it claims will out-power and out-torque the competition's largest power plants (even the V10s) with 340 hp at 4,200 rpm and 455 lbs. ft. of torque at 3,200 rpm. It too is designed to run 200,000 miles.

The third option, the standard Vortec 6000 used in the half-ton models, has been improved with 70 more horsepower (325 hp at 5,000 rpm) and 40 more lbs. ft. of torque (370 lbs. ft. at 4,000 rpm) over the 5.7-liter it replaces.

Allison tranny. To leverage this full power and torque, GM is matching the two larger engines with the 1000 series Allison 5-speed automatic transmission or the new ZF-S6-650 6-speed manual tranny.

The Allison features a commercial-class level of performance, according to GM, handling gross vehicle weights (gvw) of 19,850 lbs. and gross combination weights (gcw) of 26,000 lbs. Features include electronic controls to manage shift timing, a tow/haul mode that avoids heat buildup that an unlocked torque converter can generate under heavy loads, and automatic engine braking and shift stabilization to better handle hilly terrain under load.

Underneath the trucks, a torsion bar front suspension provides higher gvw ratings and load-carrying abilities. And when it comes to trailering, it'll tow 12,000 lbs. with a factory-installed weight-distributing hitch, or up to 16,000 lbs. with a gooseneck hitch.

To check out these new heavyweights, see your dealer this fall.