2006 Gmc Sierra 1500 Slt on 2040-cars

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GM 6.2L EcoTec V8 rated at 21 mpg by the EPA

General Motors is already laying claim to best-in-class power for its new 6.2-liter V8 that will be offered in the 2014 Chevy Silverado and GMC Sierra this fall, and now it has released fuel economy numbers for the big engine. Available as an option on the Silverado LTZ and High Country (shown above) models as well as the the Sierra SLT and Denali trims, the 6.2L EcoTec3 V8 will return 15 miles per gallon in the city and 21 mpg on the highway on rear-wheel-drive trucks; these numbers drop by one mpg each on four-wheel-drive models.
These estimates are in addition to the engine's 420 horsepower, 460 pound-feet of torque and max trailering capacity of 12,000 pounds, and considering all that power it's not terribly far away from the fuel economy of GM's equally new 4.3-liter V6 and its rating of 18 mpg city and 24 mpg highway. This announcement comes just days after a report indicated that GM is unable to keep up with the demand of the 5.3-liter V8 in the fullsize Chevy and GMC trucks due to supplier issues. GM's official press release for the 6.2-liter V8's fuel economy is posted below.

Diesel Power finds the ultimate modified oil-burner

For nine years, Diesel Power magazine has run the Diesel Power Challenge, this year's grindfest being "a week-long torture test that features seven events, nine trucks, 8,000 horsepower, and nearly 15,000 pound-feet of torque." The road to being crowned "the most powerful truck" starts with a dyno run, and then continues through the completion of a CDL-style obstacle course, an eighth-of-a-mile drag race while towing a 10,000-pound trailer, a quarter-mile drag race without a trailer, a fuel economy test in the mountains and finally a sled-pulling test through a 300-foot-long packed-mud pit.
What kind of trucks get into such a fight? Last year's winner, for instance - who upgraded his truck this year to prove he didn't "luck into the win" - drives a 2008 Ford F-250 Super Duty with a 6.4-liter Power Stroke V8 upgraded with a custom intake, Elite Diesel triple turbos and a two-stage nitrous system. Another competitor has a 2005 Dodge Ram 2500 powered by a 5.9-liter Cummins inline-six, upgraded with Garrett turbos, dual-stage nitrous, a seven-inch exhaust stack and twin fans built into the bed to cool the Sun Coast Omega transmission. The numbers on that truck: 1,255 horsepower, and 2,063 pound-feet of torque at the wheels. Naturally, as the image above might suggest, things don't always end well.
You'll find all five videos covering this years challenge below. A scene in the dyno video sums it all up perfectly: a competitor leaves his nitrous on too long and the crew is treated to some ominous poppings, he leans out the window, throws both hands up and shouts, "Amer'ca!"

GMC Syclone spools up a storm on Jay Leno's Garage

A storm was brewing on American roads in the early 1990s. That's when Detroit's automakers were producing some of the hottest performance trucks ever devised – models like the Ford Lightning, GMC Typhoon, and its flyweight pickup sibling, the GMC Syclone. Jay Leno just happens to have one of the latter in his garage, and took it out to showcase in this latest video segment. The Syclone was an exercise in absurdity, and could not only trounce any other pickup on the road, it could outrun anything else GM made and just about anything else on the road – beating Ferraris and Porsches off the line. In a pickup, for crying out loud. The kicker is that its engine wasn't such a monster, either: under the hood sat a 4.3-liter turbocharged V6 pumping out what would seem by today's standards to be an adequate 280 horsepower and 350 pound-feet of torque. Even the smaller of the EcoBoost V6s available in today's Ford F-150 produces more than that. But in a lightweight, compact pickup, those figures were enough to propel the Syclone to 60 in 4.3 seconds and run the quarter-mile in 13.6 seconds. Long before the dune-jumping Ford F-150 SVT Raptor or even the Viper-powered Dodge Ram SRT-10, GM made fewer than 3,000 Syclones based on the compact Sonoma (sister to the Chevy S-10) and another 4,700 of the Typhoon, which was mechanically similar but more practical (albeit heavier) wagon bodywork from the Jimmy. But as Jay aptly points out, the Syclone was the one you wanted. Scope it out in the ten-minute video clip above.