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2003 Hummer H2 Technical Briefing

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Hummer H2Mechanical Overview
Borrowing from General Motors, Hummer is using the proven Vortec 6000 V8 engine. Tuned for the H2, the motor uses cast aluminum heads with sequential fuel injection. The 6.0L engine is rated for 325HP at 5200rpm and has 385lb-ft of torque at 3600rpm. A special low-speed throttle progression calibration is used when the H2 is in 4LO locked mode. Behind the Vortec is the 4L65-E 4-speed automatic transmission and then the all-new Borg-Warner 44-84 transfer case.

The H2's rear axle is the familiar GM 12 bolt solid axle with disk brakes. The base rear suspension is a modified GMT820 5-link setup with variable-rate coil springs and 46mm monotube gas shocks. An optional interactive air spring suspension is available. On this suspension, an air compressor inflates each of the two airbags in the rear independently to raise the H2 in either an automatic, load-leveling mode or by a switch. The compressor uses the H2 20/20 rule, which means that it can pump up all of the tires 20 pounds in 20 minutes. See CAD Drawings #7 and #8 for full graphics.

The front suspension is a GM 25-Series utility truck independent setup using a 36mm stabilizer bar, 46mm monotube gas shocks, and tuned torsion bars.

Though the H2 began life using more of a Suburban frame, the final frame assembly is made up of 3 sections. The front uses a modified GM 2500-Series utility frame. The mid-section is all new and is completely boxed. The rear section uses a modifed GM 1500-Series frame which is upgraded for 8000 pound gross vehicle weight. Front and rear receiver mounts with 9000 pound winch capability are integrated into the frame. The rear hitch has an estimated 7000 pound capacity.

Two different tire options will be available on H2, both from BFGoodrich and will ride on 17" x 8.5" cast aluminum rims. The standard tires will be the Long Trail T/A LT285/70R17 (32.7" x 11.25") tires, while the upgraded tires will be the more aggressive and larger LT315/70R17 (34.4" x 12.40) All-Terrain T/As.

Hummer H2Exterior and Interior Overview
As we mentioned earlier, the H2 is very large and boxy like the Hummer H1. Most of the body uses standard metal body panels, however, the tilt-forward hood uses a compression-molding of SMC (sheet molding compound) inner and outer panels. This is the same compound used for Corvette body panels and is the largest SMC piece that GM makes. The hood also features the instantly-recognized radiator grill and air lift brackets found on the H1. Under inspection, however, these are for appearance only and are not in any way functional.

Climbing inside the H2 takes a bit effort, proving that this is no ordinary SUV. An optional step is available for those who need it and is easily detached when heading for the great outdoors. The interior is a combination of GM parts and all new H2 parts. The seats will look very familiar to GM truck owners. The look, shape, and feel of the leather is nearly identical that found in the Suburban, Tahoe, and Silverado/SLT pickups.

The H2 has two front seats, a bench rear seat and an optional single rear seat, providing room for six people. The rear-most seat is removable and is a single seat because the full-size spare wheel is kept in the back of the truck. So don't expect to get tons of cargo in the rear of an H2, even with the rear seats folded flat, unless you remove the spare, as well as the third row seat. If you have the air suspension option, an air outlet and switch can be found near the rear hatch for connecting an air hose.

Hummer H2We saw two different dashes in the two H2s. The Sunset Orange Metallic H2 was the older of the two trucks on-hand. The newer, final Beta version Sage Green Metallic H2 had the production dash, which includes six white-faced gauges. The entire dash is ultra-modern and has plenty of knobs to play with for controlling HVAC, radio, CD, cassette, transfer case and traction-control modes, etc. The transmission shifter looks like it came right out of an airplane and is mounted in front of the center console.

The rear seats are very comfortable and offer plenty of room for seating, however, they do sit a bit high. The new trend is to put stadium seating in SUVs, but the H2 could use a wee bit more headroom in the back if you have tall passengers. The seats fold flat just like in a Suburban or Tahoe. The headrests break away allowing the seats to go down even if the front seats are sitting back a good ways. The rear passengers get their own air vents and radio controls.

As for comfort and gadgetry, the H2 comes standard with GM's OnStar and HomeLink systems and the tunes come from a nine-speaker Bose system. The leather-wrapped steering wheel has secondary radio controls so the driver can keep their hands on the wheel. The HVAC has dual-zones for the front passengers and outlets for the rear. Six power points are found throughout the truck so you'll never have to look far for one. Side mirrors can be folded in electronically when you get into tight spaces on the trail or in the car wash. Passengers will be happy to know that there are plenty of places to grab and hold on in the H2 when the going gets rough.

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