All Envoys feature dual-stage front driver and passenger airbags. To lessen the possibility of injury caused by deployment, the airbags fire at a reduced rate for modest impacts and more quickly for severe crashes. Side curtain airbags, which protect passengers' heads in a collision or rollover, are optional. Stopping the 4,800-pound SUV are four-wheel disc brakes with dual-piston calipers and ABS. An OnStar system with recently improved voice recognition software comes standard on all models. Conspicuously absent from the options list are stability and traction control. GM remains one of the few manufacturers that don't offer stability control on their midsize SUVs--both Toyota and Ford include it as standard. Thankfully, this feature will be standard equipment on 2006 Envoys.
General Motors has endowed the base Envoy with a rather high-tech powerplant, a 4.2-liter, dual-cam straight-six that makes 275 horsepower and 275 lb-ft of torque. This engine even uses variable cam phasing, a technique that boosts top-end power. But there's no such wizardry for the 5.3-liter/300-horse pushrod V-8, standard in Denali models and optional in the Envoy XL. Both engines use the same four-speed automatic transmission. It's a shame GM doesn't provide a five- or six-speed automatic.
From the transmission, power is either routed directly to the rear wheels or through an optional transfer case for four-wheel drive. The 4WD system has three modes: rear-wheel high, four-wheel high, and four-wheel low. A locking rear differential, to help get the SUV out from between a literal rock and a hard place, is optional. With the proper powertrain combination, the Envoy can tow up to 7,100 pounds (rear-drive V-8 models), making it one of the most capable mid-size SUVs on the market.
Overall, the ride quality of the Envoy is decent. The basic suspension soaks up choppy pavement well for a truck that uses body-on-frame architecture, with more refinement available via the optional air suspension. The only drawback to the comfortable ride is the lack of feel from the road, as is the case with most midsize SUVs. Dull, over-boosted steering exaggerates the effect, along with some body roll through dynamic maneuvers in standard-suspension versions. Road noise is low, especially in the Denali models, which use extra sound insulation. Adequate acceleration is supplied from the torque-rich engine, although it would be a stretch to call the six-cylinder Envoy quick. Shifting is smooth, but another ratio in the gearbox would help both acceleration and fuel economy. While the V-8 provides more torque, it feels only marginally faster fitted to the heavier Envoy configurations; the eight-cylinder engine's appeal is seen in its towing ability.