Gone with the aerodynamic wind
By Lou Ann Hammond, Mon, 3 Apr 2006 08:00:00 PDT
"Lawdy me, Miss Scarlett, I don't know nothing 'bout birthin no babies!" Butterfly McQueen as Prissy had the third most famous quote from Gone with the Wind, the greatest film of all times if you ask anyone born and bred in the South. Georgia is deep in the heart of the South and the place General Motors decided to show off their newly redesigned GMC Yukon.
This isn't a new baby for General Motors, they've been birthin this baby for years. Tomorrow couldn't have come fast enough for General Motors new SUVs. General Motors large SUV sales are going down, but their Yukon Denali sales are up. The 2007 Yukon line-up includes Yukon, Yukon XL, Yukon Denali and Yukon XL Denali. Yukon is available in SLE (cloth trim) and SLT trim (leather), as well as 2WD and 4WD configurations. The fourth generation small-block V-8 family powers the Yukon family. A 5.3L small-block V-8 is standard at start of production in Yukon and is rated at 320 horsepower and 340 lb.-ft. of torque, an 8-percent horsepower increase compared to the previous 5.3L engine. A Flex-Fuel E85 version, which is capable of running on E85 ethanol fuel (85 percent ethanol and 15 percent gasoline) or a mixture of E85 and gasoline, is standard on 4WD models and available on 2WD models. E85 is comprised of 85 percent ethanol, which is a renewable resource fuel produced domestically. A 4.8L V-8 engine, rated at 290 horsepower will become the standard engine of Yukon 2WD base models later in the '06 model year.
Every journalist that drove the new Yukon was impressed by the changes made in interior and exterior. Gone were the days of plastic, enter the new luxury Yukon. I had just driven the Land Rover Range Rover HSE the previous week and was astounded that the liftgate didn't have a hydraulic assist. The Yukon Denali does have a power liftgate feature that makes the liftgate easy-to-operate. The liftgate is specially designed with a micro-switch that assists the operator by using the mass of the tailgate to almost open or close itself once the liftgate is past the halfway-open position.
The Yukon is full of safety items, including, Standard StabiliTrak stability control system with rollover mitigation technology, standard dual-stage driver's front air bag, standard dual-stage outboard-front passenger air bag with Passenger, sensing system, available roof-mounted head curtain side air bags for all seating rows (standard on Denali and Yukon SLT models), standard front-seat safety belt pretensioners with rear impact deployment capability, standard tire pressure monitoring system, available rain-sensing wiper system (standard on Denali ), available Ultrasonic Rear Parking Assist that can detect certain stationary objects in the rearward path of the vehicle and send an audible warning sound (standard on Denali and Yukon SLT models), available rearview camera system designed to provide the driver with a view of people or objects in the rearward path of the vehicle, standard pull-up/push-down power window switches, available voice-assisted navigation system.
There may be a few people that try the Rhett Butler, "Frankly, my dear I don't give a damn", but most people are raising the issue of fuel mileage. According to Roger Clark, GM North America Engineering senior manager of energy and drive quality, "Fuel efficiency is becoming the single mantra of General Motors. Clark has reached the GM version of NASCAR racer notoriety. At a recent presentation of the 2007 GMC Yukon and corresponding 2007 Chevy Tahoe astonished Clark remarked, "Wherever I go, everyone is interested in fuel efficiency. The goal is to seamlessly give the customer the same machine, the same size, comfort, and amenities, with increased fuel efficiency. How to you pull those really big GMC/Chevy SUV gorillas out of the Toyota Prius hat?"
It started with racers and ironically GM's full sized SUVs have become the NASCAR equivalent of race machines in drag reduction aerodynamics. "We sealed all the seams on the vehicles." noted Clark. "The 2007 running boards diffuse wheel well turbulence, reducing turbulence contributing to better mpg." The 2007 Chevy Tahoe has a .36 drag coefficient, (Best in class!) Why and what does drag coefficients have to do with the DVD, larger than you should chug "cup" holders and super-sized heated seats?Racers, both on the ground and in the air know that 'free' horsepower means going faster with the same engine, chassis, airframe. Likewise for Mr. Clark's team, their goal of better mpg for the Yukon and Tahoe, or 'free' horsepower is increased fuel efficiency instead of going faster. Forever related in the physical world, aerodynamics and mass or weight of an object determine the physical limitations for that object.
There is no silver bullet secret additive formula for fuel efficiency. Traveling at 48 mph GM's big boy SUVs have to overcome energy losses to increase fuel efficiency BEFORE the driver's habits, i.e. speeds and types of driving contribute to the vehicle's efficiency.
The 5.3L engine's Active Fuel Management technology also enables better fuel economy. When combined with other vehicle-wide features, including improved aerodynamics, the small-block V-8 helps provide the segment's best fuel economy. The 6.2L engine of the Yukon Denali is all-new, with advanced technologies and lightweight materials - including variable valve timing and an aluminum cylinder block - contributing to the vehicle's uncompromising performance. Later in the model year, a new 6.0L all-aluminum V-8 with 355 horsepower and 365 lb-ft of torque, variable valve timing and Active Fuel Management becomes available.
The competitors for the Yukon are the Chevy Tahoe, Cadillac Escalade, Ford Expedition, Nissan Armada, Toyota Sequoia, Land Rover Range Rover HSE.
The all-new 2007 Yukon XL will be offered with a starting at $37,790 MSRP, $2,440 less than the model it replaces. The Yukon XL Denali will start at $50,490 MSRP, $2,220 less than the 2006 XL Denali model. Both MSRPs include a $875 destination freight charge. The 2007 Yukon XL and Yukon XL Denali will go on sale this spring.