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2018 GMC Acadia with 'Christmas Aero' modification gets in the wind tunnel

Tis the season of "Big" - big cheer, big parties, big bowls of eggnog, big decorations, and when it comes to your family hauler, big drag. Festive drivers who festoon their crossovers, minivans, and SUVs with wreaths, Rudolph noses, fuzzy antlers, and rooftop Christmas trees undo the years of work that car engineers devote to fractional gains in fuel economy. To put numbers to such fuel-guzzling madness, GMC started with a 2018 Acadia, optioned it with the Xmas Aero Package - both Standard and Plus versions - put it in Lockheed-Martin's wind tunnel. The resulting dip in fuel economy results probably won't surprise anyone who's used a roof rack - or, for that matter, their car's air conditioning. However, it might surprise you to find out which seemingly substantial decoration had no effect, and which seemingly innocuous decoration was about twice as bad as running the A/C on its Mr. Freeze setting. Check out the brief video above for the results. And consider placement of that bow carefully.

2015 Chevy Silverado, GMC Sierra can tow up to 12,000 pounds

Think back to the launch of the 2014 Chevrolet Silverado. At the time, General Motors happily trumpeted that its fullsize pickup could tow up to 11,500 pounds when properly equipped - impressive stuff, no doubt. But now, revised tow rating practices have been put into place, called SAE J2807. And with these new methods of testing, GM can now officially rate both the Silverado and its GMC Sierra twin as being able to tow up to 12,000 pounds.
Of course, not all Silverado and Sierra models are capable of this feat. In fact, because of SAE J2807, most of the truck models have actually had decreases in tow ratings from the 2014 to 2015 model year. For example, a 2014 Silverado Crew Cab with the 5.3-liter V8, 5.7-foot box and 3.73 rear axle was rated at 11,200 pounds in 2014, but has since been reduced to 10,800 in 2015. Same goes for the Sierra.
But for 2015, both the Silverado and Sierra can be had with a more powerful 6.2-liter V8, as well as a Max Trailering Package that includes a 9.76-inch rear axle, heavy-duty rear springs, revised shock tuning, improved cooling and a new trailer brake controller. There are also four- and seven-pin, bumper-mounted connectors, a trailer hitch (duh), and a G80 locking rear differential. This configuration, with either model, is the only way you can actually tow 12,000 pounds.

Next-gen Chevy Silverado and GMC Sierra may use carbon fiber

It's been generally accepted that the next generation of full-size GM trucks will use some sort of strong, lightweight material for the beds while retaining steel for the cab. While aluminum seems like the most obvious choice, according to Automotive News, the Chevy Silverado and GMC Sierra will incorporate both aluminum and carbon fiber in their beds. The publication cites sources from within GM, though it seems the introduction of this comparatively exotic material mix is still a few years off. While carbon fiber is both stronger and lighter than steel and aluminum, it takes significantly more time and money to produce, essentially relegating the material to small-volume cars. The main benefit for trucks is the resulting reduction in weight to improve fuel economy without sacrificing the tough, rugged capabilities truck buyers expect. The Ford F-150 made the switch to aluminum for the 2015 model year and it's proved highly successful. It seemed like it was only a matter of time before the competition followed suit. Automotive News says that the next-gen trucks will launch with aluminum beds and that it will take a couple of years before we'll see any carbon fiber incorporated into the design. Even then, only look for the composite material on higher-trim models, with a trickle down to lower-spec trucks possible further in the future. In 2011, GM announced it was working with Japan-based Teijin Limited on a carbon fiber reinforced thermoplastic. There's a good chance that material's introduction will be on trucks. Related Video: News Source: Automotive News Plants/Manufacturing Rumormill Chevrolet GM GMC Truck