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VW Finds CO2 'Irregularites', SEMA Recap, and More | Autoblog Minute

Volkswagen's diesel emissions scandal gets a new wrinkle, US regulators hit Takata Corporation with a substantial fine, and we head to Vegas for a look at tuner paradise at the 2015 SEMA show. Autoblog Senior Editor Greg Migliore reports on this edition of Autoblog Minute Weekly Recap. Acura Chevrolet Honda Mazda Mitsubishi Toyota Autoblog Minute Videos Original Video Acura Legend

Chevy's 6.6-liter Duramax is pretty much all new

To say there's a heated battle in heavy-duty pickups is an understatement, with Chevrolet, Ford, and Ram constantly trading blows of increased torque, horsepower, and towing capacity. The latest salvo is the revised, more powerful turbo diesel 6.6-liter Duramax V8 in the 2017 Chevy Silverado. It has 910 pound-feet of torque, an increase of 145, putting it nearly level with the Ford Super Duty. Here's a closer look at where those gains come from. How exactly did Chevrolet add all that torque plus 48 horsepower? The automaker essentially took a fine-tooth comb to the entire engine. Chevy says it changed 90 percent of the V8, and the cumulative effect of those small changes adds up to big increases. As you might guess, the turbocharger is updated. The larger unit features electric actuation of the variable nozzle turbine (VNT), and what Chevy calls a double axle cartridge mechanism that separates the VNT moving parts from the housing. That helps with heat performance as well, with a claim that the exhaust side of the turbo can run continuously up to 1,436 degrees Fahrenheit. Helping that cause are six exhaust gaskets made of Inconel - an nickel alloy that contains chromium and iron – and upgraded stainless steel for the exhaust manifold. Despite having the same cast iron cylinder block, albeit with some minor enhancements, the engine has new cylinder heads, pistons, piston pins, connecting rods, and crankshaft, which have all been upgraded to handle 20 percent higher cylinder pressures. Alongside the increase in pressure, Chevrolet also increased the cylinder head's structure with a honeycomb design. The pattern features high-strength aluminum with dual layer water jackets that not only improve strength, but also optimize water flow for better cooling. For 2017, the cylinder head also benefits from integrated plenum that aids the engine in getting more air under heavy loads. The cylinder head isn't the only component to get a minor update, as the pistons have a larger diameter pin for improved oil flow. The same detailed improvements has been bestowed to the humble connecting rods (second in our hearts only to the inanimate carbon rod). The new design has the bolts oriented roughly 45-degrees to the rod instead of parallel. The angle split design, as it's called allows for easier passage through the cylinder.

Some 2012-13 Chevy Volts may not have enough battery coolant

The 2012 and 2013 model year Chevrolet Volt extended-range plug-in vehicle may have a battery glitch caused by low coolant levels. No recall has been issued and General Motors is taking care of the issue at no cost to drivers. Some of the affected Volts may have lower-than-advisable coolant levels because of some pesky air pockets in the car's cooling circuit. When the coolant levels get too low, the charging system for the battery powering the car's onboard generator (i.e. the Rechargeable Energy Storage System, or the RESS) may be shut down, turning one's Volt into a run-of-the-mill gas-powered car, and a pricey one at that. The Car Connection says GM is advising owners of the '12 and '13 Volts to contact their local Chevy dealer for a free fix. GM representatives didn't immediately respond to a request for comment from AutoblogGreen for more details. We believe this is a separate issue than the one that brought 8,000 Volts back to the dealers for a battery coolant fix, what GM called a "voluntary customer satisfaction effort," a few years ago. General Motors sold 23,094 Chevy Volts last year after selling 23,461 Volts in 2012, so that fix-it list may get fairly lengthy. Check out a GM-Volt.com user thread related to this issue here. *UPDATE: Chevrolet spokesman Randy Fox confirmed in an e-mail to AutoblogGreen that the company issued a service bulletin to dealers that they may need to top off coolant levels on certain Volts because of the issue, and that the vehicle will "return to normal charging operation" once that's done.