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New Car/Review

The GMC Sierra 4X4 Extended Cab Shortbed Sportside, It only gets better

by Larry Weitzman


Looks are generally personal. The new GMC Sierra pickup differentiates itself from its near identical twin brother, the Chevy Silverado, with different sheet metal. The new GMC borrows heavily from the Denali version of the Yukon and in this case I very much like the theft.

Let me be perfectly clear about this, this new GMC that I tested is the best looking pickup available anywhere. This year body parts aren't strictly interchangeable with the Chevy like in the prior generation of trucks. The front ends are completely different.

GMC choose an evolutionary styling change, carrying over their styling theme and the familiar open grill with big red GMC letters in the middle. The headlight assembly is gorgeous as it flanks the chrome grille surround. It flat out works. The look is far more integrated and smoother, without loosing the tough, powerful look you want in a truck.

The new sportside also has new more blended rear fender lines, an almost sleek look. The taillights are large and fit perfectly. This is the slickest looking truck I have ever seen and it looks stronger, more capable and nimbler than ever. I don't talk much about colors, but GMC deserves accolades for their paint color selections. The red is a real red and the Indigo Blue of my test vehicle is one of the best blues I've ever seen.

Under the hood are three new overhead valve (OHV) V-8's and a V-6 carried over from the previous generation. The OHV V-6 (which is the previous generation 5.7L V-8 with two cylinders chopped off) produces 200 hp at 4,600 rpm and a strong 260 lb-ft of torque at a low 2,800 rpm. The new V-8 family is all derived from the LS1 Corvette engine and shares the same architecture. The 4.8L V-8 puts out 255 hp (the same amount as the old 5.7L V-8) at 5,200 rpm and 285 lb-ft of torque at 4,000 rpm. The 5.3L manufactures 270 hp at 5,000 rpm and 315 lb-ft of torque at 4,000 rpm. The 6.0L makes a whopping 300 hp at 4,800 rpm and 355 lb-ft of torque at 4,000 rpm.

The bad news is that the 6.0L engine will only be available in the 2500 series heavier duty models. The good news is that GM is tinkering with a short bed sportside regular cab super sport truck with this motor. However, with a little tweaking, it dynos at an astounding 395 hp with normal aspiration. If you buy one, also buy stock in B.F. Goodrich.

In the area of performance, a penalty is paid for being a 4X4. 0-60 mph averaged 8.6 seconds with my best run at 8.2 seconds. A two-wheel drive will average about 8.0 seconds. 50-70 mph passing performance on the level was a quick 4.6 seconds, but going up hill (about 6%) slowed that time to 7.2 seconds.

The reason for the slightly slower times is that the 4X4 (versus 4X2) carries around about 300 pounds more weight, most of it stemming from the transfer case and extra differential in the front axle. This extra weight on the front end also reduces weight transfer during acceleration, further reducing performance. Remember all numbers a relative and these are terrific performance numbers in their own right. A heavy right foot will cause plenty of smiles from the strong acceleration.

Fuel economy is also effected by this extra weight. This 4X4 is EPA rated at 15/18 mpg city/highway while the same truck in a 4X2 is rated at 16/20 mpg city/highway. I averaged 15 mpg during my test period with extensive use of all of its 270 hp. I would estimate 16-17 mpg in normal El Dorado County driving and near 20 mpg on the highway at legal speeds as the engine turns only 2,000 rpm at 70 mph. Impressive.

The transmission is GM's 4L60E (4 for the amount of speeds, L for longitudinally mounted, 60 for torque rating and E for electronically controlled). It is smooth and comes with the new tow/haul switch, which reprograms the transmission for higher shift points and crisper shifting. A nice feature for downhill engine braking as well.

If you compare this performance with the previous generation 5.7L 255 hp truck, you will find more performance with 0-60 times improved by almost a second and fuel economy up by nearly two miles per gallon. That is a significant accomplishment.

New chassis developments such a partially hydroformed frame (ala Corvette), a 64 percent improvement in cab strength and greater overall structural rigidity has resulted in a chassis frequency of 23 hz. All these advances mean a better, quieter ride and improved handling.

This 4X4 has newly designed, stronger but lighter, fully independent suspension up front with huge torsion bars up front and a live (solid) axle in the rear. It tamed and smoothed Ponderosa Road, except for some slight sideways rear end movement in the two bumpy 90 degree corners. The ride is firm, well controlled but not harsh. Bigger bumps are absorbed even better. The worse the road, the better the ride.

Green Valley and Bass Lake Road were straightened by this GMC's nimble handling and accurate steering. In a run down Highway 49 to Jackson and then up Highway 88 to Pioneer, I could have imagined I was driving a sports vehicle. It handled that good. Steering was accurate with superb feel. It required a little more effort than the same truck in a 4X2. I prefer the slightly higher resistance of the 4X4.

Adding to the confidence are the massive four-wheel disc brakes with standard full antilocks and dynamic proportioning. The feel and modulation were excellent and the ABS kept the truck under full control under any braking conditions.

When the clear weather turned into rain, the AutoTrac automatic 4X4 feature of this truck gave extra confidence to its handling during the inclement weather. It senses when there is rear wheel slippage and then instantly transfers power to the front wheels as long as needed than reverts back to two-wheel drive. It worked perfectly.

Such a system is not full time four wheel drive, but gives the driver the economy of two wheel drive and the advantage of four wheel drive when necessary without having to move any levers and push any buttons. There is also a button for "part time" 4X4 high, 4X4 low and well as 4X2 high and a neutral for towing the Sierra.

This GMC will smooth the bumpiest highway. Even with its firmer suspension settings, it didn't let in tar strips or expansion joints. There is almost no wind or road noise and on asphalt pavement, it is as smooth as any vehicle, 4X4 or sedan.

The other big news in the GMC is its largest rear interior of any extended cab pickup. The new cab has four more inches of interior length and most of that is found in the aft portion of the cab. The rear seat cushion is 17 inches deep, a full two inches more than the previous generation truck and deeper than the rear seat of some small sedans. In addition there is almost three inches of new legroom with a seat back rake angle that has been increased from 14 degrees to 18 degrees. The upshot is the most comfortable rear seat in any extended cab pickup.

New for 1999 is a standard right side rear door. This improves access to the rear but GMC has yet to catch up with the industry standard, which includes two rear doors on full size pickups for Ford and Dodge. But once inside the other makes, the rear passengers won't be as happy. Ingress and egress may be a little easier, but the accommodations aren't near as good. I'll take the better accommodations.

The front seats of my test truck had the convenient 40/20/40 configuration with a large pull down armrest/storage. The driver and passenger are some of the most comfortable in the business and the middle seat is great for small people, tolerable for adults for a reasonable period. The materials used are rich and thick.

The dash is identical to the Chevy and similar to the previous model GMC. The pod in front of the contains a large speedo with a large tach flanking left and smaller temp, voltage, fuel and oil pressure to the right. A message center is in the upper left corner, which monitors fifteen functions including transmission temperature; A nice feature which will help prevent transmission damage under severe towing. The 6.0L models and the 6.5 turbo diesel come with a standard transmission temp gauge.

Just to the right of the gauges are the controls for the fine sounding am/fm stereo CD. Below the radio are the easy and simple to use HVAC system controls. There is an airbag off/on switch for the passenger.

So what's the problem. These new pickups don't come cheap. My test vehicle had a base sticker price of $27,210 plus a destination charge of $640. It also had the following options: Marketing Option Package 1SC which includes power windows, locks, cast aluminum wheels, keyless remote entry and a host of other items for $685 (a super bargain); Convenience Plus Group containing dual power seats, electrochromatic mirror and the push button active transfer case for $1,000 (another bargain); the 5.3L V-8, $700; heavy duty trailering, $285; locking rear differential, $270; larger 245/75X16 tires, $161; electric rear window defogger, $154, deep tint glass, $107, heavy duty suspension, $95. The total price was $31,307.

Prices for GMC pickups start at about $17,000 and a similar truck without four-wheel drive comes in at under $28,000. The 4.8L V-8 would do just fine in a short bed 4X2 and satisfy most drivers with the advantage of greater fuel economy (16/21 mpg) with 0-60 times in the 9 second range.



4.3L OHV V-6                  200 hp @ 4,600 rpm
                              260 lb-ft of torque @ 2,800 rpm

4.8L OHV V-8                  255 hp @ 5,200 rpm
                              285 lb-ft of torque @ 4,000 rpm

5.3L OHV V-8                  270 hp @ 5,000 rpm
                              315 lb-ft of torque @ 4,000 rpm

6.0L OHV V-8                  300 hp @ 4,800 rpm
2500 series only              355 lb-ft of torque @ 4,000 rpm


front engine (longitudinal),
rear wheel and four wheel 


5 speed manual

4 speed electronically 
controlled automatic


Wheelbase                      143.5  inches
Length                         227.5  inches
Width                          78.5   inches
Height                         73.9   inches
Ground Clearance               10     inches
Curb Weight                    4645   pounds
Tow Capacity                   7500   pounds
Axle Ratio of test truck       3.73
Fuel Capacity                  26     gallons


0-60                           8.6    seconds
50-70                          4.6    seconds
50-70 uphill                   7.2    seconds
Top Speed                      Electronically limited to about 97 mph.  
                               Without a governor I estimate about 110-120 mph
Fuel Economy                   EPA 15/18 mpg city/highway.  I estimate 16-17 mpg in
                               El Dorado County driving.  Highway mileage of
                               about 18-20 mpg at legal highway speeds.