The GMC Yukon offers a nice ride on asphalt and on dirt. It even rides with impressive smoothness on bumpy rural byways that make some other SUVs feel like pogo sticks. On smooth highways, the Yukon cruises effortlessly. Handling is impressive and surefooted for a full-size SUV. Yukon is stable at high speed. It's much easier to park then the longer Yukon XL, but it's still a full-size truck and not as maneuverable as a mid-size SUV such as the GMC Envoy or Ford Explorer.The Yukon is definitely a truck. It comes with a live rear axle supported by coil springs and located by five control links, an arrangement which provides a good compromise between ride/handling and cargo-carrying utility. Its front suspension is conventional in design, but uses torsion bars instead of coil springs to save space. Yukon's truck-like ladder frame is fully boxed in the mid-section for maximum rigidity, while the front and rear portions are shaped by hydroforming that allows for more design freedom and a more rigid frame. This rigid design is a key to the Yukon's excellent ride and handling. At the front of the frame is a section designed to crush and absorb impact in a crash.
Yukon Denali's AutoRide computer-controlled suspension helps keep it level over bumps. This benefit is especially pronounced when towing; a trailer tends to cause the towing vehicle to rock back and forth when driving over bumps, but the AutoRide system keeps the Denali amazingly smooth.
The combination of good visibility and confident handling give the Yukon an air of nimbleness in spite of its massive size and weight. The steering on all Yukons provides good control and feedback. It's a recirculating-ball system, however, which doesn't offer the response of the rack-and- pinion steering found on the Ford Expedition and Lincoln Navigator. On the other hand, recirculating-ball steering can provide better isolation than rack-and-pinion when driving on rough, unpaved roads.
Yukon's relatively tight 38.3-foot turning diameter makes it much easier to park than a Yukon XL, which takes another 4.7 feet of space to turn around. That makes a huge difference in the grocery store parking lot.
The brakes perform well. A dynamic proportioning system continuously balances the front and rear brakes for maximum effectiveness without activating the ABS. As a test, we towed a heavily laden horse trailer without trailer brakes and were impressed with the Yukon's braking ability. To reduce braking effort, GM's Hydroboost technology uses hydraulic pressure rather than engine vacuum; Hydroboost provides more power for high-deceleration stops, and improves ABS performance.
Under the hood, Yukons employ the latest heirs to Chevy's small-block V8 engine family. These Generation-3 overhead-valve engines are the best yet and rival competitors' overhead-cam engines for smoothness and efficiency. As mentioned, they come in three sizes: 4.8-liter, 5.3-liter, and 6.0-liter. All burn regular unleaded.
The popular 5.3-liter V8 offers impressive acceleration performance. Called the Vortec 5300, it's rated 295 horsepower and 335 pound-feet of torque. GMC says fuel economy has been improved for 2005, thanks in part to the new dual, 200-watt electric cooling fans that replace the engine-driven fan used previously. The electric fans are quieter, too, and the radiator is now more efficient, and GMC says we should also expect improved air conditioning performance while stuck in traffic. Fuel economy estimates for the 2005 Yukon were not available at press time, but in the Chevrolet Tahoe this same engine managed 14/18 city/highway mpg with 2WD, 13/17 with 4WD. The smaller, 4.8-liter V8 develops 285 horsepower but considerably less torque: 295 pound-feet. And it uses nearly as much fuel, rating 14/18 mpg with two- or four-wheel drive.
For 2005, the big 6.0-liter V8 that comes with the Denali cranks out 335 horsepower and 375 pound-feet of torque, thanks to better-breathing cylinder heads and refinements to the fuel injection and spark-timing calibrations. GMC says fuel economy is also improved.
Two-wheel-drive Yukons come standard with electronic traction control, and the optional limited-slip rear differential further improves traction in slippery conditions. Using the winter start feature on the automatic transmission helps get the Yukon rolling without wheel spin on snow or ice by starting it off in second gear.
StabiliTrak, which is what GM calls its electronic stability control system, offers greater safety and handling stability on slippery surfaces. It comes standard on Denali but is also available on Yukons, both 2WD ($555) and 4WD ($750). StabiliTrak measures where the driver is steering against where the truck is actually heading and, when necessary, reduces engine torque or selectively applies the brakes to one or more wheels to correct the Yukon's path. In short, StabiliTrak can help keep you from going off the road if you remember to steer where you want to go. The combination of StabiliTrak, its traction control function, and the limited-slip rear differential greatly improve the capability of 2WD models in slippery conditions; the limited-slip is standard with Stabilitrak on 2005 models.
It seems a shame to pass on the four-wheel-drive system, however, especially where winter brings snow. Four-wheel-drive Yukons rely on a traditional part-time 4WD system, but with somewhat sophisticated electronic control called Autotrac. Press the 4HI button when standard four-wheel drive is needed for driving off-road or on roads covered with snow and ice. You may never need the 4LO setting, but it's invaluable when creeping through deep sand, deep mud, deep snow, or up and down steep grades.
More typical are those wintry days when conditions are fluctuating and the roads are a mixture of ice, snow and wet pavement. When this happens, hit the Auto 4WD button, and the Autotrac all-wheel-drive system automatically transfers power from a slipping wheel to the wheels with the best traction. Autotrac also works well in pouring rain and on gravel roads.
Yukon Denali comes with full-time all-wheel drive, relying on an open center differential and a front/rear torque split of 40/60 for yaw stability. StabiliTrak is standard on Denali, and combined with Denali's full-time all-wheel drive helps maintain good traction in changing conditions. It's also a good system for snow, ice, heavy rain, dirt, and gravel.
All Yukons come equipped to accept a lighting plug for trailer towing, and have provisions for easily connecting a trailer brake controller. All have a Tow/Haul mode for the automatic transmission that reduces wear when pulling a trailer through hilly terrain. Pressing the Tow/Haul switch on the end of the shifter reduces the tendency of the transmission to hunt back and forth between third and fourth gears. When the transmission does shift, it shifts more quickly, reducing heat buildup for improved durability and reliability. Even when not towing, we sometimes like to use the Tow/Haul mode for crisper shifting on mountainous roads.
The Denali works particularly well for towing. The bigger engine helps pull trailers up long grades, while the all-wheel-drive system is just the ticket for pulling a boat trailer up a slippery boat ramp. For drivers' peace of mind while towing, the Denali features a transmission temperature gauge, so you can be confident that you are not cooking the gearbox while pulling a trailer up a hill. Denali's heavy-duty M32 automatic transmission is made with hardened parts to withstand the extra power of the 6.0-liter engine.
Add your own review or comments
