Although the Chevrolet Silverado is far and away the volume leader in General Motors' truck stable, the GMC Sierra serves an important supplemental role in providing additional sales for customers that might not otherwise set foot in a Chevrolet showroom, as well as for those looking for something a little different from the mainstream. Prior to their public unveiling in December, GM promised more differentiation between the two models for 2014. Now that we've seen them, we can say that statement is true, to an extent. But the 2014 Sierra is still clearly related to its predecessor, as well as its bowtie brother.

Fresher, Still Familiar

Side-by-side with its predecessor, the 2014 Sierra doesn't look drastically different at first glance. The familiar three-bar grille and squarish headlights remain, but the stylistic aggression has been amped up a notch or two on the 2014 via a more protruding front grille and a higher hood height -- as high as the Sierra 2500 HD, according to GM. And what now seems like an almost mandatory styling flourish these days, LED driving lights are included on several trim levels, including SLT, All-Terrain, and Denali. Although Chevrolet points out projector beam headlights in the Silverado, it appears the LED driving and directional lights may be exclusive to the Sierra, at least for now. Standard on the Sierra SLE and SLT trims and optional on select Silverado models, LED lights under the bed rail improve bed visibility in the dark. Both Sierra and Silverado feature built-in steps in the rear bumper to aid access to the bed.

The biggest functional change for both the 2014 Silverado and Sierra is the adoption of front-hinged doors on the extended-cab models, following in the footsteps of Ram's Quad Cab, which adopted the front-hinged doors in 2002. The doors on both models go from a top wraparound design to a flush-side mount design. The doors are also triple-sealed as part of an effort to further quell wind noise. New for 2014 on both the Silverado and Sierra is the availability of a 6'6" bed on Crew Cab models, which were formerly available only with a 5'8" box. The longer bed is the only one available on extended cab models.

The Sierra also features more stylized wheels than the Silverado. As was the case with the 2013 model, sizes range from 17 to 20 inches in diameter, though width increases by a half inch for 2014. Customers that believe in going big or going home will be able to buy GM-tested and approved 22-inch wheels as accessory options. A more notable change happens behind the wheels. Whereas most 2013 trim levels featured front disc and rear drum brakes, the 2014 Sierra and Silverado both feature standard discs at all four corners.

Official specifications including weight, wheelbase, length, and other key measurements have not yet been released, but from the looks of things, they may grow an inch or two in most directions.

The Inside Story

As before, the interiors of the Sierra and Silverado are virtually identical apart from some minor details, though both are considerable improvements over those of their predecessors. MyLink and IntelliLink may be branded distinctly between Chevrolet and GMC, but functionally, the systems are essentially the same. Both include HD Radio, Pandora streaming internet radio, and a customizable favorites list with up to 60 entries, including radio presets, phonebook listings, music and destinations.

Although hard and fast equipment details on the two trucks are still not available at this point, a feature available for both trucks are heated seats with cloth upholstery. Available in the Sierra is GM's Driver Alert Seat, pioneered in the Cadillac XTS, which vibrates on the left or right side of the driver's seat cushion, indicating perpendicular oncoming traffic when the driver is backing up. The driver can select audible or vibrating alerts. (It's called the Safety Alert Seat in the Silverado, and is also optional there.) Both trucks also offer optional front park assist.

New Engines, Same Displacement

Both the 2014 Chevrolet Silverado and 2014 Sierra get all-new engines, though the displacements carry over from 2013. The engine lineup starts out with a practically clean-sheet 4.3-liter overhead-valve V-6. Some observers may see the introduction of an all-new pushrod V-6 in this day and age as laughably retrograde or backwards, but GM saw some compelling reasons to stick with the tried-and-true OHV layout for the base engine, as opposed to adopting the 3.6-liter "high-feature" DOHC V-6 for truck duty.

The new V-6 is based on the new fifth-generation family of small-block V-8s, and as such, receives the same aluminum block and heads, direct injection, and cylinder deactivation technology. Official output figures for the new V-6 have not been released, but GM claims the engine will provide ample power for a crew cab truck plus a trailer. In a further vote of confidence in its entry-level mill, the V-6 is available for the first time in a crew or extended-cab 4x4 configuration.

The base V-6 also shares its high 11:1 compression ratio with the new fifth-generation 5.3-liter V-8. The optional 6.2-liter V-8 gets a slightly higher 11.5:1 compression optimized for premium fuel. In percentage terms, we're expecting the biggest gains for the V-6, since it was based on the generation-older original small-block architecture, rather than the newer LS1 (Gen III and IV) engines. We're confidently predicting output levels in the ballpark of 280 hp and 300 lb-ft of torque for the V-6. Guesses for the 5.3 and 6.2 are a little more speculative, but we're going with between 355-375 hp and 365-385 lb-ft for the 5.3, and 430-450 hp and around 450 lb-ft of torque on the 6.2.

Silverado Invading Denali Territory?

Not specifically mentioned at the Silverado and Sierra's introduction was the rumored "High Country" edition Silverado, which was reported earlier this fall. From the description we heard, it would be a luxury trim above the LTZ that would feature many premium features such as heated and cooled seats, stitched leather trim, and a western theme similar to the Ram Laramie Longhorn and Ford King Ranch. Although maybe more "country" in theme than the Sierra Denali's more sophisticated, understated style, content-wise the rumored availability of the High Country package begs the question of whether or not there is too much product overlap between the Silverado and Sierra. Some believe the introduction of the High Country model would move the Denali trim even further upmarket on the Sierra, filling in the gap left by the likely discontinuation of the Avalanche-based Cadillac Escalade EXT. Since many GMC and Cadillac dealers share showroom space, this could be a smart marketing play, but will be a test of brand loyalty, as some customers may go for a lower-priced, but comparably equipped Silverado model.

Too Safe or Functionally Focused?

Almost immediately after the new trucks were revealed, some pundits and critics criticized the new models for not being a radical enough change from their predecessors. The full-size truck market is indeed a highly competitive segment, and a perception of being dated, less capable, and less efficient is certainly not a something any truck maker wants to be saddled with. On the flipside, being recognizable and familiar can also be a strength since many buyers have an "if it isn't broke, don't fix it" mentality.

The previous Vortec 4300 V-6 and four-speed combo was clearly outdated, arguably by as much as a decade. The EcoTec3 V-6 seems like a long-needed and worthwhile update. The power and efficiency gains with the V-8 engines will likely be appreciated by buyers and may appeal to skeptics that still aren't fully onboard the EcoBoost bandwagon. Without a doubt, the new Sierra will appeal to GMC loyalists and may get a few conquest buyers, but jury on how many F-150s, Rams, and Tundras show up as trade-ins will be out until these trucks hit the showrooms.

From what you've seen so far, do you think the Sierra and Silverado will take a big bite out of Ford and Ram sales, or just bring back loyalists for a trade-in? Share your thoughts below.