Diesel and Hybrid SUV Comparison

By dancurranjr On May 13th, 2009

chevy-tahoeMany of you have probably read our Diesel and Hybrid SUV Comparison wondering where the GM representative is. After deciding on a 4WD/AWD diesel versus hybrid comparison test, we then had to make sure the SUVs we included would be similarly equipped. Therefore, the Tahoe, Yukon, and Escalade hybrids were eliminated as contenders because they all come standard with a third row. That alone could’ve made this an unfair comparison. But despite that, some of you still may wonder how one of these vehicles would’ve lined up against the BMW (which charges $1700 for the optional third row), Mercedes-Benz, Volkswagen, and Lexus. Here’s a general overview.

The base prices for the vehicles in this comparison vary from an estimated $42,000 for the RX 450h to $51,200 for the X5. The 4WD Tahoe Hybrid starts at $54,210 ($54,680 for the Yukon) and the AWD Escalade hybrid is $76,635 before adding accessories. The Tahoe Hybrid’s price is about $12,000 over a base 4WD and $9000 more than an LT2 trim level; Hybrid content falls between the LT2 and LTZ grades. An Escalade Hybrid is roughly $11,000 more than an Escalade AWD, and the Platinum trim package adds another $11,750.

The GM hybrids all use the same powertrain: a 6.0-liter gasoline V-8 and dual electric motor units sandwiched in the four-speed automatic transmission, rated at 332 horsepower and 367 pound-feet total output. This betters the comparison-test fleet’s horsepower by at least 67, but it’s the second-worst torque. (Those with more torque are diesels. What else would you expect?) While they have some weight-saving features to limit the hybrid penalty to roughly 350 pounds–similar to adding 4WD to a rear-drive SUV–they still have 5850-6050 pounds (empty) to haul around.

The GMs’ wheelbase, at 116.0 inches, is longer than the longest wheelbase tested here, the 115.5-inch X5. Track is widest front and rear, and its 202.0-inch length is significantly longer than anything else here. The next-longest vehicle, the X5, is 11 inches shorter. The GMs have the most front-row headroom and overall shoulder room, yet interior dimensions are midpack otherwise. It stomps the rest in cargo volume, though–108.9 cubic feet of storage behind the front row as opposed to 75.2 for the X5, 72.4 for the ML, and 71.0 for the Touareg.

On the road, the big GM hybrid ‘utes feel much like the standard versions when friends are on board. The brake pedal is touchier, and sidling into a tight garage or parking spot might not be as smooth as you’re used to. Golf buddies and lanky families of four or five will be more comfortable in the hybrid GMs than their conventional counterparts. The hybrids use unique front seats for weight savings and they seem as comfortable as the regular seats, but they aren’t as thick so there’s a significant increase in second-row knee space. The GM hybrids all use a bench-seat second row because of the battery pack beneath it, and as the widest SUVs around, they do well at three-across seating on that middle bench. The Tahoe/Yukon/Escalade use a three-person bench with two headrests and a 50/50 split to remove them for a flat cargo floor.

When we tested a 2WD GMC Yukon Hybrid, it did the 0-to-60 sprint in 8.3 seconds and the quarter mile in 16.2 at 88 mph. A nearly identical-weight 4WD Tahoe LT non-hybrid posted 8.3 seconds to 60 and 16.1 at 86 mph in the quarter mile; these and the 45-65 times are all in the same spectrum as the ML and Touareg diesels.

We have no directly com- parative fuel economy data. However, on 70-mile loops that included Interstate, urban, and winding roads all between 100 and 1500 feet above sea level, a Tahoe Hybrid delivered 19.8 mpg, right on its 20 city/20 highway mpg rating; a Yukon 5.3 brought 17.7 (14/20).

In the two-mode hybrids, when you mash the pedal from a stop, as you might to cross a highway, there’s a momentary delay before the gas engine is lit and full thrust comes on, and while the reasons are different, the effect is very similar to the from-rest turbo lag in some diesels. The Escalade Hybrid’s mileage is likely to be slightly lower than that of the Tahoe and Yukon, maybe 1.0 mpg, because it doesn’t have the same aero tweaks, adds 100-200 pounds, and in most instances will be optioned with 22-inch wheels.

Despite the torque from electric drive, the GM hybrids are limited to 12,000 pounds gross combined, so maximum tow rating is 6200 pounds (2WD Tahoe/Yukon). That’s better than that of the RX (3500) and X5 (6000), but falls short of the ML’s (7200) and Touareg’s (7716). For towing on open highways, we’d probably recommend a standard 5.3-liter Tahoe/Yukon, rated at 8400/8200 (RWD/4WD).

The Tahoe and Yukon Hybrids come as 2WD or 4WD vehicles; the Hybrid is the only Escalade with low-range gearing–though apart from scaling a slimy launch ramp, we can’t imagine anyone will ever use it. Ground clearance matches that of non-hybrid models’ and the Hybrids’ cleaner side steps might last longer in the rough stuff, but the bits modified for aero and weight benefits–deeper front air dam, 18-inch wheels, and higher-pressure, low-rolling-resistance tires–all work against off-highway performance. GM does not list fording depth for any of these utilities, hybrid or otherwise.

Would it have been unfair to include the Tahoe or Yukon in this comparison story? Probably, considering that they’re much larger vehicles than those tested here and come standard with three rows of seats. However, when you think about the capability you get for a comparable price, putting the GM SUVs in this context does make for some interesting conversations.

SOURCE: Truck Trend

GMC, Chevy Hybrid Pickups Deliver Fuel Economy

By dancurranjr On April 23rd, 2009

sierra_hybrid_truck_r350x200Working on the theory that saving fuel is most important in the vehicles that consume the most, General Motors has introduced the GMC Sierra and Chevrolet Silverado hybrid pickup trucks.

Already out in Yukon and Tahoe SUVs, the two-mode hybrid was developed in a joint venture with Chrysler and BMW. The idea came about as a scaled-down version of GM’s hybrid bus drive train and is especially well-suited to vehicles that need some towing and hauling capability. The system is distinct from most other hybrid systems because it can automatically run on straight mechanical power as well as pure electric or a combination of the two.

Based on the reengineered Sierra and Silverado pickups that debuted in 2007, the hybrids look the same as the crew cab versions of the base trucks with the exception of some hybrid badges, optional hybrid graphics and a standard tonneau cover that helps out aerodynamics. The battery pack is underneath the rear seat, and the hybrid drive unit is about the same size as the transmission it replaces. It contains two compact electric motors (one reverses field to generate power) and four mechanical gears.

The two-mode hybrid system sees the most advantage in city driving, so GM planned an all-city driving route as the first demonstration for the press. Starting off in a four-wheel-drive Sierra rated at 20 mpg n in both city and highway driving, I clocked an indicated average of 22.3 mpg over approximately 75 minutes of driving.

The small print in the EPA ratings do say 16 to 24 mpg is the “expected range for most drivers.” I was driving conservatively, but not to the extent of holding up traffic. My driving partner for the day nearly duplicated my efforts on the return trip with a 22 average mpg reading.

Like other hybrids, the engine shuts off when the vehicle is stopped so as not to idle unnecessarily. When you start moving again, the hybrid pickups are capable of driving up to a stated 30 mph on electric power alone. The gasoline engine starts up automatically and seamlessly when it is needed.

As I had experienced previously in a GMC Yukon hybrid, it was difficult to start moving at a normal rate without the engine kicking in. However, once it was rolling with a steady throttle input, the engine would turn off and we were able to run up to around 28 mph on electric power for a quarter mile or so at a time. Above that, engine power would do the driving duties.

Ideally, at the 35 mph cruising speeds we were getting, the truck would run on hybrid power, a combination of gas engine and electric drive, but this seemed hard to maintain unless we were on a longer stretch at steady speed. When you back off the accelerator and coast, the batteries start recharging. The 6.0-liter V-8 engine will also automatically cruise in four-cylinder mode for extra fuel savings.

Next, two Sierra and Silverado hybrids were hooked to trailers and others were loaded with 800 pounds in their beds. We took a drive towing a 5,400-pound Sea Ray boat with inertia brakes on the trailer. The hybrid was able to pull the boat in electric mode up to 15 mph. When briskly accelerating from a stop, the hybrid felt especially potent.

I asked lead development engineer John Turzewski what was the hybrid drive’s equivalent to first gear.

“You have infinite gear ratios,” he said “The 6.0-liter will do zero-to-60 in 8.4 seconds, plus you get the additional assist of the electric motors, which is instantaneous.”

In that regard, the hybrid might even be better for towing than a conventional truck, not to mention more fuel efficient. The short towing test loop resulted in a quite respectable indicated 15 mpg.

The Silverado and Sierra hybrids do deliver as promised, and the hybrid drive functions in a silent, seamless manner. However, their advantage can only be used to its full potential in a fairly narrow set of circumstances. Extensive city driving, perhaps as a delivery truck or a longer stop-and-go commute are some areas where the hybrids would excel in efficiency. On short trips, especially in cold weather, you won’t see any savings over a similar gas-only pickup with cylinder deactivation, as the engine must be fully warmed up before the hybrid drive starts functioning.

Yukon and Tahoe hybrid SUVs hit the market last year only fully loaded at upper-end sticker prices; GM has made the price of admission for the pickups more affordable with a decently equipped package starting at $38,995, including destination. Probably not low enough to save money in the long run at today’s gas prices, but it’s still a compelling product and an impressive engineering achievement.

SOURCE: Search Chicago

First Look: 2009 GMC Yukon Denali Hybrid

By dancurranjr On April 15th, 2009

gmc-denali-yukonIn what just seems to be a move to bolster its hybrid portfolio, GM is unveiling the 2009 GMC Yukon Denali Hybrid at the 2009 New York auto show.

Like the recently announced Cadillac Escalade Platinum Hybrid, the Yukon Denali Hybrid takes the 2-Mode hybrid system offered in the base Yukon model, but applies it to the brand’s top-tier SUV offering. As is the case with “normal” Yukon and Yukon Denali models, the Denali Hybrid adds features (e.g. a custom grille, 22-inch wheels, ) that aren’t offered on the Yukon Hybrid.

The 332-hp, 6.0-liter V-8 underhood, however, is identical to those used in GM’s other full-size hybrid trucks. So too is the 2-mode hybrid transmission, which switches between an infinitely variable mixture of gasoline and electric power to fixed gearing when needed. GM says the system allows the Yukon Denali Hybrid to achieve 21/22 mpg city/highway with rear-wheel-drive.

GM expects Yukon Denali Hybrids to arrive at GMC dealers in May. Two-wheel-drive models will start at $59,185, while four-wheel-drive carry a base price of $62,030.

SOURCE: Automobile

Find a great deal on a GMC Yukon

2009 GMC Yukon Hybrid: 2009 New York Auto Show

By dancurranjr On April 12th, 2009

gmc-yukon-hybridWhat Is It?
2009 GMC Yukon Hybrid

The Specs
The Yukon Hybrid is the third GM body-on-frame SUV to receive the two-mode hybrid technology. GMC says the Yukon will seat 8 passengers, tow 5800 pounds and return around 21 mpg in city conditions. The hybrid powertrain is the same as the system used in the Tahoe and that includes the 332 hp 6.0-liter V8. To differentiate the Yukon, GMC has fitted the big SUV with GM’s MagnaRide suspension, which utilizes the same magnetorheological shock technology that’s used on the Corvette ZR1 to adjust the damping rate based on road conditions.

The Bottom Line
GM’s two-mode hybrid system is impressive, delivering a big percentage improvement in fuel economy. But the mpg numbers, in the low 20s, could be a tough sell for many traditional hybrid owners. The 2WD version of the GMC hybrid starts at $59,185. 4WD versions begin at $62,000.

SOURCE: Popular Mechanics

GM: Hybrid Drive A Good Fit For Pickups

By dancurranjr On March 17th, 2009

gmIn today’s falling market for full-size pickups, towing capability is more important than ever, General Motors Corp. believes. And that, it says, is one reason for its recent four point gain in market share, to 42 percent, in the segment.

According to AutoTech Daily, GM figures more buyers will embrace the new hybrid-electric versions of the Chevrolet Silverado and GMC Sierra currently being launched by the company. The new pickups are fitted with the same two-mode hybrid system — teamed with a 6.0-liter V-8 engine — offered on the 2008-model Chevy Tahoe, GMC Yukon and Cadillac Escalade hybrids.

GM says the two-mode powertrain,which has four fixed gears as well as a planetary gear that combinesthe output of the gasoline and two electric motors, is a good fit for the pickups. The additional gear ratios improve towing capacity — 6,100 pounds for two-wheel-drive versions of the Chevy/GMC pickups — including in all-electric mode at speeds up to 30 mph. Although towing capacity is down significantly from the traditionally powered counterparts (9,700 lbs for a 2wd extended cab truck), GM says its system provides more oomph than Ford and Toyota’s hybrid trucks, which top out at 3,500 and 1,000 pounds, respectively.

Refinements also have been made to other parts of the pickups to better complement the hybrid system and optimize fuel economy, which is listed at 21 mpg in the city and 22 on the highway in the two-wheel-drive model, up 40 percent in the city and 25 percent overall compared
to gasoline-only models.

The 300-volt nickel-metal hydride battery drives the 42-volt electric steering unit through a DC-to-DC converter. In addition to recharging the battery, regenerative braking helps extend the life of the regular brake linings.

The 2010 pickups also get low-rolling-resistance tires. A new exhaust system is tuned specifically for the V-8’s cylinder deactivation
system — which cuts cylinders under partial-load operation.

A new hydraulic shock mount on the cab helps reduce vibration. The feature also will be included in GM’s non-hybrid pickups. In the hybrid models, the system is teamed with a new low-noise electric cooling fan for the battery pack.

Despite the benefits, GM expects fewer than 15 percent of its full-size pickup buyers to opt for the hybrid system. This compares to a 25 percent take rate for the Escalade hybrid, which GM says is one of the highest rates for a hybrid drive in vehicles that offer it as an option. The hybrid versions of the Tahoe/Yukon account for about 15 percent of Chevy/GMC full-size SUV sales.

The two-mode hybrid system was developed in partnership with DaimlerChrysler and BMW. Chrysler briefly offered the system in the Durango and Aspen before killing both vehicles in the face of the company’s economic woes. BMW will launch its version in the new X6 crossover later this year. GM also plans to offer the system in the Saturn Vue, although the program has been delayed and is somewhat questionable considering the future of Saturn itself is in jeopardy.

SOURCE: WWJ News Radio