2001 Gmc Sierra 2500 Duramax Diesel on 2040-cars

Auto blog

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.

2013 GMC Acadia Denali

Refreshed, Not Refreshing
I'm probably ill-suited to accurately and fairly take the full measure of a vehicle like the 2013 GMC Acadia Denali. This is a machine conjured around the express notion of corralling and then herding a brood of rafter-swinging hatchlings to and fro in relative comfort, and with no such passel of wee Bowmans to call my own, it's difficult to give this rig a fair shake. While I can certainly weigh cargo capacity, legroom and fuel economy stats with the best of them, I'd be lying to your face if I said the word "crossover" didn't urge some uncontrollable Pavlovian recoil from the murky recesses of my frame. To put it simply, I just can't stand the damn things.
As a rule, the segment is built on a bed of compromise. Manufacturers love nothing more than to spin up a tired yarn about the virtues of this particular neck of the market. We're told the crossbreeds deliver all the ride quality, driving dynamics and fuel economy of a car married with the seating position, capability and interior volume of the SUV set. That all sounds as swell as a sunset, but as the 2013 Acadia Denali so artfully illustrates, the advertising on the box is rarely congruous with the prize inside. Even with an imaginary squad of younglings at my heels, the refreshed luxury crossover doesn't quite manage to scratch the promised itches.

Surprise! GM putting aluminum in next-gen pickups

Last month, General Motors launched a series of ads touting the benefits of steel over aluminum – specifically, with regard to the Chevy Silverado versus the Ford F-150. (Kind of. We're not sure what a grizzly bear has to do with anything.) We took issue with the ads, with editor in chief Mike Austin saying they "reek of insecurity, and distract from the Silverado's strengths that could be used for positive advertising." But what bothers us more, is that yet another report surfaced claiming anti-aluminum GM will indeed use the weight-saving material in its next-generation fullsize trucks. On Tuesday, GM announced a $877-million investment for its truck plant in Flint, MI. But Reuters says that huge overhaul is because the trucks will use "substantially different equipment than the tools GM uses today." The report specifically states, "People familiar with the company's plans say GM's next-generation pickups and SUVs will make use of various materials, including aluminum and lightweight steel, to shed weight and gain fuel efficiency to meet tougher federal standards." The Silverado already uses a few aluminum components in the engine and hood, and if more widespread use will help GM build its best fullsize trucks ever, then that's great. Honestly, we have no reason to doubt that aluminum will be used in the next Silverado and GMC Sierra. We just hope GM remembers that nothing is ever truly deleted from the bowels of the Internet when it launches the subsequent "look how great aluminum is!" campaign. Related Video: News Source: Reuters Green Plants/Manufacturing Chevrolet GM GMC Truck aluminum steel