2014 Chevrolet Silverado: Developing a Truck for Workaday Performance
People who buy trucks take them seriously. People who design, engineer and produce them do, too. Because chances are, they also drive trucks. The 2014 Chevrolet Silverado is a case in point.
So you have a vehicle that repre-sents 24.3% of your company’s sales—bigger, by far, than any other model in the lineup. In 2012, 418,312 were sold.
And now it is time for a new one.
It is the full-size pickup, the Chevrolet Silverado. Chris Perry, global vice president of Chevy marketing, says, without exaggeration, that it is the most important vehicle in the GM portfolio. Not just Chevy. GM.
And so it is time for a redesign. For re-engineering. For a new lineup of the light truck.
What do you do?
From the standpoint of the exterior, the answer seems to be, “Not a whole lot.” That is, while there are several new improvements and adjustments, the fundamental Chevy character still remains. There are the dual-port grille and double-stacked headlights. But there are new grille treatments and the head-lamps are the parabola types that tend to be found on upscale sedans, and the lights stretch further to the corners of the front end. There is a one-piece chrome bumper and a large Chevy bowtie adorning the front end. Chris Hilts, who is the creative design manager for the interior designs of GM’s truck lineup, says that his colleagues on the exterior side of the business used the theme “Fist into the wind” when developing the front end of the truck. There are power bulges on the hood, like those used on the heavy-duty versions of the Silverado, and there is a slight tuck in on the body sides such that the bumper flares front and back create a slight Coke-bottle shape.
If you look more closely, you’ll find things like redesigned doors. In previous models, the tops of the doors wrapped over the top of the roof. On the 2014 Silverado they are fitted into the body side. (This contributes to a considerable reduction of noise in the cabin—that design, as well as the use of new triple door seals.)
They spent a considerable amount of time refining the vehicle in the GM wind tunnel at its Technical Center in Warren, MI. Again, there were a variety of tweaks, like the design of the aforementioned headlamps, which actually route air around the front of the vehicle. New side-view mirrors, again to help manage air flow (and to also help reduce noise: realize that because mirrors are located right outside where the driver and front seat passengers are located, they can contribute to a considerable amount of perceptible noise). The front air dam is tailored, not uniform in shape (the norm in fullsize trucks): the Silverado’s front air dam is higher at the centerline and lower at the corners. There are rear deflectors located in front of the rear wheels to help reduce drag. The tail lamps are tapered. There is an under-truck splash shield which also works to smooth airflow. And they did a fundamentally better job at creating a tight fit between elements including the hood, fenders, bumper, grille, and headlamps.
The crew cab configuration has a coefficient of drag of 0.41. This is about 5% better than the previous-generation achieved.
If you go to the inside of the vehicle, where Hilts and his colleagues worked, then you don’t need to look closely to discover that there are significant changes. The last-generation truck’s interior was predicated on the design of a car interior. That is, there is horizontal dominance of what are various components and surfaces constructed with hard plastics that are meant to resemble materials that are either soft or wood or metal but which pretty much look like hard plastics. Overall, it is low, with things like “wood” trim that are about as convincing as “Tokyo” in the original Godzilla.
Things are different for the 2014. There are levels of refinement. That said, Hilts says, “This interior is upright and truck-like.” There is a sense of truck-like blockiness. Again, not in a brutal way, but with attention to detail. “There is truth to materials,” Hilts says. If the trim appears soft, then it is soft. If it appears hard . . . But if it appears to be wood, well . . .
It is no exaggeration to say that there are “Truck Guys” (with the “guy” being gender-neutral) and there is everybody else. Jeff Luke is a Truck Guy. Personally (yes, he drives a pickup). And especially professionally. He is the GM executive chief engineer, Global Full-size and Midsize Trucks. He started with GM in 1986 as a GMI Engineering and Management Institute co-op student at the Scarborough Van Assembly Center. (GMI is now Kettering University. Scarborough Van is now the site of a shopping mall.)
According to Luke, the carryover from the last-generation Silverado to this one is approxi-mately “a bag of fasteners.” They went at every aspect. Yes, like the last one there are the hydroformed frame rails and boxed sections. Luke says they took about 30 lb. out of that structure. The hood is aluminum, the first time for a Silverado. It provides a weight-save of 17 lb.
They’ve deployed a game-changing quantity of high- and ultra-high-strength steels in constructing the cab. In all, the steels account for about 67% of the cab. It is worth noting that the strong materials are put where they are needed and not where they aren’t: the roof rails are made with HSLA and press-hardened steel while the roof itself is mild steel.
Presumably, some of those fasteners that Luke mentioned may be found in the engine, because GM developed a new line of engines—named “EcoTec3”—for use in the truck. There are a 4.3-liter V6 and a pair of V8s: 5.3- and 6.2-liter.
A primary objective, explains Jordan Lee, Small Block chief engineer and program manager (and a guy who worked on the engine for the 2014 Corvette [6.2-liter LT1]), was to develop engines that are truck-oriented, which means delivering the kind of torque needed by, well, trucks. So the 4.3-liter delivers 305 lb-ft of torque, which is said to be the most of any standard V6 in the business.
Of course, trucks don’t always return the best fuel economy, so that was a key consideration, too. Notably, the 5.3-liter V8, when in a two-wheel drive Silverado, is expected to deliver an EPA-estimated 23 mpg highway. No slouch, it is SAE-certified at 383 lb-ft of torque and 355 hp.
(Speaking of torque: the 4.3-liter V6 produces 305 lb-ft, which GM claims is the most of any standard V6.)
One of the things that GM has been doing with serious intent of late has been to increase the utilization of their computer modeling resources for powertrain development. As noted, Lee worked on the 6.2-liter LT1 . . . a Small Block engine, like the 6.2-liter EcoTec3. GM Powertrain engineers spent 10-million CPU hours developing the overall engine design, of which 6-million hours were dedicated to the combustion system design.
The engines feature direct fuel injectors. There is a new cylinder head design; the heads have smaller combustion chambers that are designed to work in conjunction with the sculpted piston head topography. The heads have large, rectangular intake ports and feature a slight twist to facilitate mixing the air. The compression ratio for the engines is at least 11.0:1.
The engines feature cylinder deactivation, so that the V8s and the V6 can operate as V4s under light load conditions. The system uses oil pressure to deactivate lifters on selective cylinders, keeping them closed until the powertrain control module indicates that they’re needed: the transition takes less than 20 milliseconds.
When it comes to the box, Jeff Luke points out that they’ve made a number of modifications that are simple and effective. For example, he points out that rather than having some sort of additional mechanism for climbing into the box, there is a notch on both sides of the corners of the bumper (they call it a “CornerStep bumper”) and a redesign of the openings in the box rail protection so that there are hand grips: Simply insert a foot into the notch and grab the handgrip in the opening, and climb right in.
One thing that is used in luxury cars to indicate the level of luxuriousness is a glovebox that opens slowly, using dampeners. This sort of thing is also used on the Silverado, but in a different place and in a different way and for a different reason. They’ve deployed an internal torsion bar and rotary damper in the tailgate so that it is (a) easier to open and close thanks to the mechanical advantage offered by the torsion bar and (b) opens in a controlled, gradual manner, thanks to the damper. (They call it the “EZ Lift-and-Lower” tailgate—functionally it is far more clever than that name.)
The truck is available with three box sizes (5-ft, 8-in; 6-ft, 6-in; 8-ft). In the case of all, the floor is produced via roll forming rather than stamping, as is the norm with other light trucks. There is a functional advantage of roll forming vs. stamping. Roll forming allows the use of steel that is stronger and thinner than that used when stamping is deployed because the roll forming is a more-gradual process, so achieving the draw is achieved without concerns with tearing the steel as could occur during conventional stamping operations.
One of the consequences of the Great Recession was that the number of light trucks produced and purchased both declined. While there has been a rebound, there are many people who discovered that their trucks could work for the long haul: GM estimates that the average age of a light truck today is on the order to 10.4 years.
The 2014 Silverado seems to have been designed, engineered and built so that round about 2024 it will still be relevant and capable.
Nowadays in the U.S. market, vehicle manufacturers pretty much are all committed to producing crossover utility vehicles rather than their predecessor type, the sport utility vehicle.
By James Gaffney, Product Engineer, Precision Grinding and Patrick D. Redington, Manager, Precision Grinding Business Unit, Norton Company (Worcester, MA)
Hyundai enters the American market with a new parallel hybrid system that uses lithium-polymer batteries and the same six-speed automatic found in non-hybrid versions of the 2011 Sonata.