TechnologyTell

High Sierra: Low Noise in the 2014 GMC Sierra

Sections: Car Audio, Chassis, Infotainment, Powertrain

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2014 GMC Sierra Photo Shoot 021

(Lyndon Johnson photo)

Chevrolet makes a lot of hay talking about how quiet its new Silverado is. Logically, its sister GMC Sierra proved church mouse quiet, too.

It’s no surprise to me that trucks I tested previous to the Sierra’s joining my driveway for a week have featured a fair amount of exhaust reverberation at speed. Both the 2013 Nissan Titan PRO-4X and the 2014 Toyota Tundra 1794 Edition transmitted plenty of exhaust noise into the cabin at highway cruising speed or when accelerating away from traffic lights.

But the 2014 GMC Sierra was whispery after initial startup, which surprised me. Its EcoTec 3 5.3-liter V8 engine purred at just a tick over 500 RPM at idle, virtually unhearable by my ears. Some engine sound entered the cabin while accelerating from a stop, but not as much as those previous trucks. At cruising speeds of 55 to 70 MPH, wind noise — which was also admirably low-level, though perhaps more noticeable because of the engine’s quietness — was only a slight intrusion into conversation.

My Dad always said GMCs are the Cadillacs of pickup trucks when loaded up with the options our SLT featured — leather seats, sunroof, and the newest iteration of GMC’s IntelliLink infotainment system, for starters — but in this truck, the most Cadillac-like quality was the sublime quietude in the cabin while driving. Unless you wanted noise in the form of an open window or music pumping out the speakers, the GMC Sierra would coddle you with quietness.

The biggest test of quietness I could think of, lacking as I do the expensive decibel metering equipment used by autojournos who have far more time and money than I, was to call my wife on the IntelliLink system’s Bluetooth hands-free calling feature. I was able to speak at a volume I might use at an intimate dinner, and she could hear me plainly. That’s probably a tip of the hat to the IntelliLink system’s microphone quality, too, but the hushed interior made for less competing noise. By comparison, the Bluetooth unit in our 2010 Nissan cube is fighting an uphill battle of the wind noise brought on by a box-shaped car, far less sound isolation, and what is likely a far less-refined Bluetooth microphone.

2014 GMC Sierra Photo Shoot 022

The lining on the outside of the 2014 GMC Sierra’s wheel wells feels a bit like sea sponge to the touch and is one of many small ways GMC made the truck so quiet. (Lyndon Johnson photo)

How far did the GMC engineers go to ensure the truck’s quietness? Check out the material in the outside wheel well skirting. It feels almost spongy to the touch — like real, hard sea sponge, if you’ve ever felt one — and surely helps absorb wind and road noise caught in the wheel wells. Door seals were thick, supple, and in triplicate. The windshield angle was raked back more for 2014 to cut down on wind noise. Panel gaps were tightened all over and mirrors redesigned to reduce places for wind noise to develop. Overall, this is the old-school “blocking and tackling” of vehicle engineering, and in the case of the GMC Sierra, it pays off in a big way.

I’ve read that 2014 GMC Sierras with the optional 6.2-liter V8 have the added option of an active noise cancellation system. Perhaps that engine is more vociferous than the 5.3-liter unit, for I can’t imagine anyone wanting additional noise-canceling technology in the 5.3-equipped GMC Sierra we tested.

Disclosure: GMC provided the vehicle, insurance, and a tank of gas.

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