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

’09 Sierra Hybrid Hits Pickup Market

By dancurranjr On April 14th, 2009

sierra_hybrid_truck_r350x200Efficient, fuel-sipping hybrid technology is available in the full-size pickup segment. The 2009 GMC Sierra Hybrid pickup – with its 6,100-pound towing capability – gets 21 miles per gallon city, 22 mpg highway.

On first blush, these fuel economy numbers may not appear so impressive, but they are. General Motors reports that they are a 40 percent improvement in city economy over the standard full-size truck. Consider these figures: A comparable standard 6.0-liter V-8 gets 13 mpg city. Now that makes the 21-mpg, 6.0-liter V-8 hybrid stand up and get noticed.

The full-size GMC Sierra Hybrid is offered as a five- to six-passenger, four-door crew cab for 2009. The test truck was a 4WD model (2WD also offered), with a base price of $41,540. The truck had just one option, the $275 six-way power driver’s seat. The destination charge on the 2009 truck is $975, bringing the final price on this 2009 hybrid pickup to $42,790.

The overhead valve 6.0-liter Vortec V-8 with active fuel management is coupled to GM’s two-mode hybrid transmission with four fixed gears and a 300-volt nickel-metal-hydride energy-storage system. GM’s hybrid component parts have a warranty of eight years/100,000 miles. One of the jobs of the 300-volt system is to provide air conditioning, even when the gasoline engine is not running.

The continuous electric variable transmission lets the Sierra pickup start up and operate at up to 30 mph on the electricity system and is designed for the tremendous trailering capability, according to GM. The benefit of the active fuel management is the cylinder cut-off operation that lets the V-8 truck run economically in a V-4 mode. The GMC Sierra hybrid 2WD pickup, with a 26-gallon gas tank, has a full tank driving range of 500 miles; the 4WD model drives on a full tank for about 470 miles.

The Sierra Hybrid 4WD returns just slightly less than the 2WD in gas economy with 20/20 mpg fuel ratings. While the 2WD Sierra Hybrid tows up to 6,100 pounds, the 4WD model has a maximum trailering of 5,900 pounds.

Besides the better fuel ratings, one of the other more notable characteristics of a hybrid is its hushed, quiet operation. This also is evident in the 2009 Sierra Hybrid’s huge passenger cabin. Aiding in the quiet ride that we experienced on the test drive were the new exhaust system for the 6.0-liter active fuel management operation, engine induction tuning, plus quiet-tuned, 18-inch low-rolling resistance tires for road-noise reduction.

In addition, the 2009 Sierra Hybrid’s Z85 suspension system features uniquely tuned shocks and a new hydraulic mount that the automaker says smooths out a choppy ride over the rough bumps on rugged road surfaces.

GMC’s body-on-frame pickup with four full-swing wide doors has a short box cargo bed and a payload rating of 1,418 pounds on the 4WD tester. The 2WD pickup payload increases to a capacity rating of 1,459 pounds. Stadium-style seating with a 60/40-split fold is the arrangement in the rear seat of the crew cab.

The Sierra full-size pickup has a five-star frontal crash-test rating from the National Highway Traffic Safety Administration. The 2009 Sierra Hybrid pickup comes standard equipped with StabiliTrak. And a stronger frame and body structure is designed to provide increased compatibility with other vehicles.

Sierra Hybrid is a full-size capable pickup designed with work capability, passenger comfort and fuel economy. It’s also about the quietest pickup on the road today.

SOURCE: Washington Times

Sierra, Silverado Take Hybrid Trucks to Next Level

By dancurranjr On April 11th, 2009

silveradoWhat kind of idiot builds a 20-mpg hybrid pickup truck? Everybody knows that hybrids are 40-mpg-plus small cars like the Toyota Prius.

As often happens when you look beyond the obvious, what “everybody knows” is wrong.

Switching from a conventional pickup to the new 2009 Chevrolet Silverado or GMC Sierra hybrid pickup actually saves more gasoline than trading a fuel-efficient compact car for a Prius.

Add the fact that automakers sell millions of pickups annually and hybrid pickups start to look smart, despite their high cost.

Using the EPA’s calculations, here’s how the numbers add up:

A pickup owner will save about 181 gallons of gasoline annually by switching from the most fuel-efficient conventional pickups – the Chevrolet Silverado, Ford F-150 and GMC Sierra – to a hybrid Silverado or Sierra.

That compares with saving 168 gallons by driving a Toyota Prius rather than the most fuel-efficient conventional compact cars, the Chevrolet Cobalt XFE, Kia Rio or Toyota Corolla.

Thirteen gallons a year won’t save the polar ice caps or end America’s oil dependency, of course.

Various pieces of hybrid technology will find their way into every type of vehicle over the next few years as automakers increase fuel economy and reduce emissions.

Unless you think pickups will join the polar bear on the endangered species list – and if you feel that way, don’t share it with a farmer, carpenter, gardener or the host of small-businesspeople who need pickups – the question becomes not whether to use hybrid tech in pickups, but how to do it well.

The 2009 Chevrolet Silverado and GMC Sierra crew cab pickups do it well, despite a few shortcomings.

They combine GM’s proven 6.0-liter V8 engine with the slick dual-mode hybrid system GM developed with BMW, Chrysler and Daimler. The system dramatically improves fuel economy without reducing towing or payload capabilities.

Prices for the hybrid pickups start at $38,020 for a rear-drive Silverado and $38,390 for a rear-drive Sierra. Four-wheel drive models start at $41,170 for the Silverado and $41,540 for Sierra.

Both hybrids come only in four-door crew cab models and cost about $4,000 more than comparable non-hybrid models.

I tested a nicely equipped four-wheel drive $41,445 Silverado and a loaded four-wheel drive $47,675 Sierra. All prices exclude destination charges.

The EPA rates the four-wheel drive hybrid pickups I tested at 20 mpg in the city and 20 mpg on the highway. Rear-drive models scored 21 mpg city and 22 mpg on the highway.

Those figures beat other full-size pickups by a whopping 6 to 8 mpg in the city and 3 to 5 mpg on the highway.

Over more than a week of driving that included highway trips and plenty of city driving, the Silverado and Sierra I tested matched or slightly exceeded the EPA’s projections.

The hybrid system functioned smoothly, routinely shutting the engine off and powering the trucks in all-electric mode at speeds up to about 30 mph on surface streets.

The system’s ability to provide power at highway speeds – unique to GM’s pickups and SUVs, and the reason the automaker calls it a two-mode hybrid – allowed the V8 to shut down four cylinders in steady highway cruising at up to 70 mph.

That’s the key to the improved highway fuel economy. Most hybrid systems only work in city driving, making the system dead weight in the highway runs the EPA says account for around 45 percent of most Americans driving.

The hybrid pickups can tow up to 6,100 pounds and offer plenty of passenger space in their roomy crew cabs.

The battery pack under the rear seat eliminates the ability to fold the seat up to increase interior cargo space, but the trucks’ functionality and comfort are otherwise unchanged from GM’s conventional pickups. The lid for the door to the upper of the trucks’ two gloveboxes was slightly misaligned, but fit and finish were otherwise fine.

The engine shut-off and four-cylinder modes function imperceptibly, with no vibration to tell the driver the hybrid system is at work.

Brake feel, however, is poor. The pedals feel stiff and provide very little feedback, making it difficult to modulate them for smooth stops. The electric power steering felt heavy at low speeds and could also use further refinement.

The fuel economy is unbeatable, however, and the ability to drive a 5,000-pound-plus all-wheel drive crew cab pickup as an electric vehicle for blocks at a time elevates the 2009 Chevrolet Silverado and GMC Sierra pickups to a level where they simply have no peer.

SOURCE: Modesto Bee

Mercedes Benz will Showcase Production ML450 Hybrid in New York

By dancurranjr On April 7th, 2009

mercedes-benz-ml-450-hybridNext week’s New York Auto Show will see the debut of three brand new Mercedes Benz models, as well as the U.S. debuts of the 2010 model year E-Class Sedan and Coupe. The trio of world firsts includes the recently revealed E63 AMG performance saloon, a facelifted GL-Class, and the production version of the ML450 Hybrid SUV.

Set to join the S400 BlueHybrid sedan in showrooms later this year, the new ML450 Hybrid will arrive as a 2010 model and is claimed to offer similar performance to the V8-powered ML550. The ML450 Hybrid will be based on the concept version unveiled at 2007’s Frankfurt Motor Show and will come with a 3.5L petrol V6 mated to an electric motor.

The system is the same one found in the S400 BlueHybrid, which means power comes from a 279hp (205kW) 3.5L V6 engine and a 20hp (15kW) electric motor running on lithium-ion batteries. Fuel efficiency gains are made through a combination of technologies, including stop-start functionality, which helps to cut fuel use while standing still at traffic lights or jams. Around town the ML450 Hybrid will also be able to cruise on electric power alone for short distances and low speeds.

But improved efficiency isn’t the only effect the hybrid system has – it can also boost performance for brief periods. By kicking in the electric motor’s full 118lb-ft (160Nm) of torque as the fuel-intensive acceleration phase kicks in, it speeds take-off while minimizing fuel use. Regenerative braking helps to maximize efficiency and recapture energy that would otherwise be lost. All of the operation of the hybrid system is displayed for the driver’s convenience in a single display in the instrument cluster.

More details, including actual fuel-economy estimates, should be released at the car’s unveiling at next week’s show.

SOURCE: Motor Authority