2006 Chevrolet Trailblazer EXT

A confusing byproduct of the rewarding Trailblazer is this sluggish EXT mammoth with no trait that resembles the driving dynamic of its instigator.

Background
This midsize SUV was acquired as a rental vehicle with 5,000 miles on the odometer at the time of pick up. It stayed with us for 3 days. We drove approximately 700 miles. We traveled from the Bay Area to Reno and back via I-80 encountering traffic congestions, long section of hilly inclines and declines, and attempting to attack corners at “posted” freeway speed. The entire trip in the Trailblazer was with 6 average size adults. The averaged fuel consumption was 18 mpg.

Introduction
General Motor introduced the brand new Chevrolet Trailblazer in 2002 to replace the aging Blazer. GM continuously reveal the standard wheelbase Trailblazer equivalent models in its lineup since its introduction but with different equipment and aesthetic packages – models included Buick Rainer, GMC Envoy, Isuzu Ascender, Oldsmobile Bravada, and Saab 9-7x. The standard and available engines are 4.2L inline 6, and 5.3L V8. The TrailBlazer remains its fundamental since its introduction without major changes. The tester is the EXT LS trim, which has extended-length chassis, with the standard 4.2L Vortech I-6 engine. The engine is longitudinally mounted, driving the 4 speed automatic O/D transmission (GM’s Hydro-Matic 4L60-E). The engine power is then transmitted to the electrically controlled four-wheel drive transfer case to divert engine power to the proper wheels depending on pavement conditions. The Michigan built engine pumps out 291hp@6,000rpm and 277Ib-ft of torque @ 4,800rpm. GM claims that 90% of the maximum torque output is available from 1,600 to 5,600rpm. Traction is provided by a set of P245/65R17 Continental Contitrac TR tires. The body-on-frame chassis (GMT370) is supported by independent coil spring-over-shocks, short and long arms suspension with stabilizer bar in the front; the rears are multilink rigid axle suspension with separated coil springs and shocks. Stopping power is generated by four-wheel ventilated disc brakes with ABS.

Impression
“Look maybe deceiving,” is no longer valid for this Trailblazer EXT. It’s obviously massive body line assembled its semi-truck like driving dynamics. The EXT drives a lot differently then the standard length Trailblazer that we’ve previously driven. We found the standard length Trailblazer LS to be quite nimble around the corners, and with responsive acceleration and passing power for being a SUV. The extra length and additional weight to the chassis, however, greatly upset the EXT’s balance.

The equipped engine in the EXT provides just adequate around town power when unladed. When fully loaded with passengers and cargos, the engine makes more noise than go. Often times the engine is just laboring to haul the EXT’s own ~5,200Ibs curb weight. Plus six passengers and a trunk-load of cargo during our test, seems to be a handful for the EXT to handle. On paper and during our times with the standard Trailblazer, and this EXT, the engine is in favor of midrange to high rpm output with noticeable power increase above 4,500rpm – maximum torque output is at 4,800rpm, and max horsepower appears at 6,000rpm with fuel cut at 6,500rpm (a very refreshing change in spec for GM). The engine is state-of-the-art in GM’s standard back in 2002. This Vortec 4200 I-6 featuring variable valve timing on the exhaust cam, DOHC with roller followers on hydraulic lifters, 4 valves per cylinder, aluminum head and block, electronic throttle control, and not to mention composite intake manifold. A quick jab on the accelerator with the transmission in neutral, the engine response is instant with throaty exhaust note in return. This straight six engine emits quality sound and remained smooth throughout most rev range, but it ain’t no match with BMW’s straight six either, where the Vortex exhibits a hint of coarseness when the needle in the tachometer approaches 4,500rpm and seems to run out of breath near 6,000rpm. Even though, the engine has been proven to be fun when equipped in the standard version, however this Vortec engine’s characteristic made the heavy-weighted EXT more sluggish at low rpm.

The word sluggish also applies to the equipped 4-speed transmission. The sluggishness comes from the long gear ratios, and the gears are too far apart to take advantage of the engine power band between shifts. The transmission has a hard time keeping the engine at the power range regardless vehicle speed. 1st gear seems to be too long for the engine to propel this mammoth out from a complete stop. At 70mph, the engine is revving at lazy 2,000rpm to try to achieve better fuel economy. A deeper punch to the throttle is often needed for the transmission to kickdown to a gear or two when passing. The shifting quality feels dated. The insufficient gearing is also seems old-fashioned for today’s standard, where 5-speed automatic transmission with electronic manual gear selection is the norm. A 5-speed gear box is definitely needed in the EXT to lessen the gap between each gear and to provide quicker shifting to keep the engine rpm in the proper range when accelerating, and cruising.

The word sluggish doesn’t stop just yet. We are able to associate sluggish to the handling aspects of this EXT. By all means, we are not trying to compare the EXT’s handling to a sporty sedan, but we wouldn’t expect such of degrade from the standard Trailblazer. The steering is lack of feedback, and on center feel. Combine with the occasionally “floaty-feel” (especially when fully loaded) suspension, and its 75″ exterior width. The EXT is a handful to drive on a proper course – in the typical 12′ wide lane on the freeway. The equipped Bilstein shocks adsorbed pavement imperfection nicely, and allowed minimum amount of road feel to intrude. The suspension setup seems fine when not fully loaded, and road feel thru the front suspension is there but a little vague. The ride and handling just misbehaves when fully-loaded when most of the weight is at the rear of the truck, causing the front end to lose grip and becomes “fluttery”. The rear solid axle with coil springs setup seems underrated to account for the load capacity.