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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.

Chevy Volt replacement battery cost varies wildly, up to $34,000

There's a growing hubbub in the plug-in vehicle community over what looks like some ridiculously cheap replacement batteries for the Chevrolet Volt going up for sale. GM Parts Online, for example, is selling a replacement Volt battery with an MSRP of $2,994.64 but, with an online discount, the price comes down to $2,305.88. For the 16-kWh pack in the 2012 Volt, that comes to a very low $144.11 per kilowatt hour (kWH). But is it a real deal? How can it be, when a Chevy dealer may quote you a price of up to $34,000 to replace the pack? For a 16-kWh Volt pack, $2,305.88 comes to a very low $144.11 per kWh. But is it a real deal? Battery packs in alternative propulsion vehicles are usually priced by the kWh and, historically, they've been thought to be in the range of $500-per-kWh for OEM offerings. Since automakers are understandably secretive about their costs, we still don't know what the real number is today, but we do know it varies by automaker. Tesla, for example, has said it pays less than $200-per-kWH at the cell level but, of course, a constructed pack would be more. Whatever is going on, li-ion battery prices are trending downward. So, $144.11 certainly sounds great, but what's the story here? Kevin Kelly, manager of electrification technology communications for General Motors, reminded AutoblogGreen that GM Parts Online is not the official GM parts website and that, "the costs indicated on the site are not what we would charge our dealers or owners for a replacement battery. There would be no cost to the Volt owner if their battery needs replacement or repair while the battery is under the eight year/100,000 mile limited warranty coverage provided by Chevrolet." A single price tag also can't be accurate for everyone, Kelly said. "If the customer needs to have their battery repaired beyond the warranty, the cost to them would vary depending on what needs to be replaced or repaired (i.e. number of modules, which specific internal components need replacement, etc.)." he said. "So, it's hard for us to tell you exactly what the cost would be to the customer because it varies depending on what might need to be repaired/replaced. As a result, the core charge would vary." But, is the $2,300 price even accurate for anyone? Thanks to a reader comment, we see that this similar item on New GM Parts makes it look like the lithium-ion modules that Kelly mentioned – where a lot of the expensive bits are – are not included.

Autoblog's top 50 car photos of 2016

This one shouldn't need much explanation. We like cars a whole lot, and that includes not just driving them but taking great pictures of them. We've collected our 50 favorite images from this year in the mega-gallery above. It's a mix of old and new, with a healthy dose of vintage and modern race cars mixed in, and not one single shot under the harsh lights of an auto show. So click through and enjoy. Featured Gallery Autoblog's Top 50 Photos of 2016 View 50 Photos Image Credit: Copyright 2016 Autoblog.com Audi BMW Chevrolet Dodge Ferrari Ford Lamborghini Mazda McLaren Mercedes-Benz Porsche Rolls-Royce Volvo Convertible Coupe Motorcycle Luxury Racing Vehicles Performance Supercars Classics