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How GM engineers are using diaper 'snow' to keep you warm

Testing how snow affects General Motors' vehicles isn't really a problem right now for the company's engineers, but in the dog days of summer the process isn't exactly easy. The only real option is for them to book time at the automaker's climatic wind tunnel. However, a flash of brilliance from an engineer allows snow to be simulated regardless of the temperature outside, and the discovery is all because of his daughter's wet diaper. The realization came to GM Thermal Systems engineer Nicholas Jahn while he was swimming with his daughter and noticed how her diaper ballooned in size in the water. He found out the substance that makes this possible is called sodium polyacrylate. When the material gets wet it grows and forms fluffy flakes that are a close imitation of snow. Best of all, the stuff can be prepared easily any time of the year, and it's reusable. The engineering team uses the material to test the effectiveness of the heating systems of GM's vehicles. They spread the sodium polyacrylate over the inlets at the base of the windshield to obstruct the airflow and then crank the heater. After some time, they can see how much is being sucked into the system and design more efficient systems in the future. See how the process works in the video above and read about the diaper discovery in GM's press release below. Diapers Change Chevy Cruze Winter Warm-up Time GM validation engineer uses diaper material "snow" to reduce frigid drives 2015-01-06 DETROIT – An item commonly found on an infant's changing table is helping General Motors' engineers simulate snow year round, ensuring heating systems in cars like the 2015 Chevrolet Cruze can quickly and efficiently warm its interior. Packed snow can prevent air from entering the inlet panel at the bottom of the windshield, obstructing the flow of air into the heating system and reducing the amount of air it can push out. This can lead to less efficient warming of the car's interior and windshield defrosting. "The last thing anyone wants to do when it's freezing cold out is scrape their windshield," said Nicholas Jahn, GM Vehicle Thermal Systems engineer. "The testing we perform on the Chevrolet Cruze with the diaper material allows us to maximize the car's heating capabilities." Ironically, Jahn stumbled upon his diaper-based testing method in the middle of summer. During a swim with his daughter, he noticed her diaper multiplied in size when it came into contact with water.

2014 Chevrolet Silverado and GMC Sierra debut all-new designs, three new engines

General Motors has finally dropped the curtain on the 2014 Chevrolet Silverado and 2014 GMC Sierra. Both trucks have undergone substantial revisions with updated versions of the company's 4.3-liter V6, 5.3-liter V8 and 6.2-liter V8 engines. In a shot across the bows of both Ford and Chrysler, GM says it won't use a V6 engine adapted from passenger car applications. Instead, it developed the 4.3-liter engine based on its proven truck-duty architecture.
All three mills will boast direct injection fuel systems as well as a new cylinder head design. Combined with a revised piston, the new engines feature a smaller combustion chamber with a compression ratio of 11:1 or higher depending on the application. Cylinder deactivation and continuously variable valve timing are all part of the recipe, and each engine is paired with a six-speed automatic transmission with auto grade breaking. So far, no fuel economy or horsepower figures have been released, though GM says the new engines will best their predecessors in both areas.
Outside, the trucks feature a number of enhancements to reduce drag and wind noise, and GM claims both the Silverado and Sierra will offer buyers some of the quietest cabins in the class. Extended cab models now feature front-hinged rear doors to allow easier access to the back passenger area, and Crew Cab buyers can now select between a five-foot, eight-inch bed or a six-foot, six-inch bed. Buyers with a mind toward going off road will also rejoice in the return of the Z71 package, complete with Rancho shocks, front tow hooks and additional under-body protection.

Recharge Wrap-up: EV torque secrets, UC Davis maps future of biofuels

A UC Davis white paper maps out "Three Routes Forward for Biofuels," balancing investment risk with carbon benefits. The first option is "incremental," in which we tinker with the existing biofuel manufacturing infrastructure for small improvements over time. The "transitional" plan suggests integrating cellulosic production and other innovations with existing operations. The third route, called "leapfrogging," would mean building refineries based on new technology such as cellulosic and algae-based biofuels. The paper suggests ways the US could use these three routes together in different areas, and predicts the payoffs in terms of carbon emissions could be significant if the right people are willing to risk the capital. After all, financial advisers are always telling investors to diversify their portfolios to manage risk and rewards in the same way. Read more over at the UC Davis Institute of Transportation Studies. The Formula E Long Beach ePrix will offer free admission. The seventh round of the inaugural all-electric race season, which was moved from Los Angeles to the streets of Long Beach, will offer fans free grandstand and general admission. The race, which takes place on April 5, 2015, will use a 1.6-mile portion of IndyCar's Grand Prix of Long Beach. Read more at LA Times. Polaris is now offering its 2015 GEM electric vehicles, including the new street-legal eM1400 LSV. The passenger and utility vehicles come in two- to six-passenger configurations, many of which are street legal on roads with posted speed limits of up to 35 miles per hour. The eM1400 LSV utility vehicle seats two, offers 1,250 pounds of payload, 1,250 pounds of towing capacity, a top speed of 25 mph and a range of up to 45 miles. Its on-board charger plugs into any standard 110-volt outlet. Read more at Hybrid Cars and check out all the different configurations yourself at the Polaris website. In EVs, more torque does not always equal faster. Green Car Reports found this out when driving the Fiat 500e (with 147 pound-feet) against the similarly weighted Chevrolet Spark EV (with 400 pound-feet). The secret is, at least in part, in the gearing. The Fiat has a 9.6:1 reduction gear, making it quicker at lower speeds despite having far less available torque, while the Chevy uses a 3:1 ratio. The trade-off though, is in top speed. Furthermore, Chevy electronically limits the torque delivery at low speeds, as 400 pound-feet is a lot of launch for the little Spark EV to handle.