1991 Chevrolet Caprice Classic Ltz Sedan 4-door 5.7l on 2040-cars

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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.

GM executive chief EV engineer says reducing cost of plug-in vehicles is 'huge priority'

As we know, another major automaker investing heavily in electrified vehicles is General Motors, and it's doing things much differently than rivals BMW, Ford or Nissan. The Chevrolet Volt extended-range EV is a modest seller at its $35,000 sticker price but a huge hit with owners. The Chevy Spark BEV, still in limited availability, puts smiley faces on its owners and drivers. The just-introduced Cadillac ELR, a sharp-looking, fun-driving $76,000 luxocoupe take on the Volt's EREV mechanicals, has admittedly low sales expectations. With this interesting trio in showrooms and much more in the works, the third vehicle electrification leader I collared for an interview at Detroit's North American International Auto Show (see #1 and #2) was Pam Fletcher, GM's executive chief engineer, Electrified Vehicles. ABG: Why do your EREVs need four-cylinder power to extend their range when BMW's i3 makes do with an optional 650 cc two-banger? "We designed [the Volt and the ELR] to go anywhere, any time" - Pam Fletcher PF: I get that question all the time: why not something smaller? You don't really need that much. You use the electric to its ability, then you just need to limp. But we designed those cars to go anywhere, any time, and we don't want their performance to be compromised. If you're driving through the mountains, we don't want you to be crawling up grades, or to be limited on any terrain. So it's optimized to be able to travel literally the biggest grades and mountain roads around the globe at posted speeds. Because what if you can't? Another good reason: when the engine is on, you have to run it wide open throttle, max speed, most of the time. And while we can do a lot with acoustics, and the ELR has active noise cancelation, a small-displacement, low cylinder-count engine at high speed, high load all the time isn't something you want to live with. That's how we came up with the balance we did among the key factors of performance, NVH [noise, vibration and harshness] and range. ABG: Where you go from here? Is the range-extender engine due for an update? PF: We know and love the current Volt, and there is still a lot of acclaim about it, so we think it's a good recipe. But we are heavily in the midst of engineering the next-generation car, which I think everyone will love and be excited about.

GM recalls 3.6 million vehicles for airbag-software problems

The Basics: General Motors is recalling 3.64 million vehicles across its lineup for an airbag-related issue. The recall covers the 2014-2015 Buick LaCrosse, Chevrolet SS, and Spark EV; 2014-2017 Chevrolet Corvette, Trax, Caprice PPV, Silverado 1500, Buick Encore, and GMC Sierra 1500; and 2015-2017 Chevrolet Tahoe, Suburban, Silverado HD, GMC Yukon, Yukon XL, Sierra HD, Cadillac Escalade, and Escalade ESV. The Problem: Affected vehicles have a sensing and diagnostic module that controls the airbags and seat-belt pretensioners. The software it uses has a defect that can prompt the module to run a diagnostic test under specific driving conditions, which will also deactivate the front airbags and pretensioners. This means that it would be possible for those safety systems to not activate in a crash, potentially leading to injury or death. Injuries/Deaths: General Motors began an investigation that led to the recall after a 2014 Silverado was involved in a crash in which the airbags did not deploy. No information was given as to injuries or deaths. The Fix: Owners can bring their vehicles to a local General Motors dealer where a software update will be installed to fix the issue. The fix will be free of charge. If you own one: General Motors will contact owners of affected cars, and owners can check whether their vehicles are affected by visiting entering their vehicle identification numbers at either the GM Owner Center website or the NHTSA website. Owners can then schedule a time to have the update installed. Related Video: