ABG First Drive: 2009 Chrysler Aspen/Dodge Durango 2-Mode hybrids

Click the Aspen Hybrid for a high-res gallery

This summer, Chrysler hits the market with the 2-Mode hybrid Dodge Durango and Chrysler Aspen. Chrysler and former owner Daimler partnered with General Motors and BMW back in 2006 to help bring the 2-Mode hybrid system to light-duty vehicles. The setup was originally developed for use in buses by Allison transmission when it was a part of GM.

The 2-Mode transmission made its passenger vehicle debut last year in the Chevy Tahoe and GMC Yukon. Built by General Motors at its Baltimore, MD transmission plant, the GM and Chrysler systems have identical internals, but there are some packaging differences where the units mate up to the two manufacturers' engines and transfer cases. We attended Chrysler's New England launch event for the hybrid Aspen and Durango. Read on to see our initial driving impressions.

Photos Copyright ©2008 Sam Abuelsamid / Weblogs, Inc.

The Aspen and Durango are Chrysler's first series production hybrids, and aside from some styling and interior trim differences, they're identical. Primary power comes from a 5.7L HEMI V8, with the 2-Mode system blending in the electric drive. That electrical energy is stored under the second-row seat in a 300-volt nickel metal hydride battery pack supplied by Panasonic EV Energy.

Unlike GM, which offers its 2-Mode trucks in rear- or all-wheel drive, the Chryslers are AWD-only. Chrysler notes that this lets them maximize the amount of available regenerative braking, but the other reason for going all-wheel-drive had more to do with the balance sheets: customers opt for AWD on 60 percent of conventionally-powered Durangos and Aspens sold. As such, Chrysler marketers concluded that combination would be the best option for the hybrids.

We gathered at the Portland Head Light in Portland, Maine, where a number of the hybrid SUVs were waiting for us. After the obligatory briefing from the Chrysler reps, we mounted up and headed south along the Atlantic coast for Boston. For those of you unfamiliar with Chrysler's SUVs, they're virtually the same size as the Tahoe and Yukon, giving up 3 inches in girth to the GM trucks, but weighing in at a substantial 700 pounds less.

Chrysler has been roundly and fairly criticized in recent years over the quality (or lack thereof) of its interiors. The Aspen and Durango cabins won't win any awards for style, but their general layout is good, with controls where they ought to be, and aside from overly plasticky wood trim, the interiors work quite well. The light gray primary color scheme inside the Aspen we drove lends the truck an airy quality that probably helps, too. One standout problem area, however, is front corner visibility, which is hindered by very thick A-pillars.

On the road, it's clear that Chrysler engineers spent a lot of time refining the hybrids. When we drove a prototype a year ago, one of the most noticeable flaws was the rough transition between regenerative and friction braking. Not so on the production models, where the only way to distinguish between regen, friction and blended braking is to watch the energy flow meter in the center stack. Brake pedal feel is a bit spongy, though, and the steering would benefit from better feedback as well. While there's little slop in the wheel and the weighting is OK, there really isn't any communication about what's happening where the tires meet the pavement. Overall, however, the Aspen's chassis delivers a very quiet and comfortable drive that doesn't wander on the road and absorbs rough pavement reasonably well.

There is, however, plenty of communication about the energy flow in the vehicle. The tachometer in the main cluster is replaced by an efficiency gauge that monitors the driver's powertrain demands. Hit the gas too hard and the needle swings to the right-hand power zone; under braking it goes to the left-hand charging zone. Most of the time you want to try and keep it right in the middle. Even more detailed information can be seen on the primary LCD display, where the "Hybrid Energy Center" provides a graphical representation of the powertrain behavior, including an engine graphic that lights up halfway or fully to indicate whether the HEMI is operating in V4 or V8 mode.

While Chrysler may have passed on expensive aluminum body parts and lightweight seats, it has implemented other efficiency measures, such as a humidity sensor in the electrically driven air conditioner. When the humidity level is elevated, the climate control chills the air more to compensate for the perceived heat. However, when the humidity is lower it backs off. The goal is to control the temperature to optimize the perceived comfort of the occupants while minimizing energy use. The other usual subsystems like the power steering have also been electrified to cut parasitic losses.

At one of the stops along our drive, Chrysler had a pair vehicles setup for towing demonstrations. We took an Aspen with a 4,200 lb horse trailer over a 5-mile test loop and found the combination of the HEMI V8 and hybrid system to be up to the task. Acceleration was no problem and slowing down was aided by the regenerative braking. The addition of regen braking to these types of vehicles should prove advantageous when descending mountain passes, helping to keep the friction brakes from overheating. The stability control system also includes trailer sway control that selectively applies the brakes when it senses a trailer beginning to move around too much. Fortunately, we didn't get to sample this feature.

Over the course of the 150 miles or so from Portland to Boston, we drove through a number of towns and along every kind of road, ending on the streets of Beantown in the hours following the Celtics celebration parade. By the time we reached the Liberty Hotel, our final destination, the average fuel economy display was reading 22.1 mpg. This won't challenge smaller hybrid cars but it's excellent for such large vehicle. Along one stretch through a small town in Maine, we managed to keep the Aspen in electric-only mode virtually the entire way -- over a mile. The engine only started briefly going up a hill and then shut off after cresting it. The final EPA numbers haven't been released yet, but Chrysler is expecting the SUVs to be rated at 19 mpg city and 20 mpg highway. The highway number matches the 4WD GM hybrids while the city number is 1 mpg lower.

Chrysler realizes that the launch timing of these vehicles couldn't have been much worse. Nonetheless, the automaker still feels that there's a market for the hybrids and is pricing them aggressively compared to GM's offerings. Those who desire such a vehicle might want to think about the mileage in terms of people miles per gallon. If you actually take multiple passengers regularly via activities like carpooling, that 22 mpg could translate into a much higher number. If there are four people who would otherwise be driving four cars, that's 88 pmpg . Of course, this calculation only works if you are taking other cars off the road and doing so on a regular basis. If however, you do displace multiple vehicles with one larger vehicle, the savings could be significant.

Even with that in mind, it's still going to be a tough road for Chrysler until it can get the hybrids into some smaller vehicles. Chrysler execs have stressed that they are indeed doing that, with the minivans and Journey crossover rumored as candidates, but the Ram is the only one confirmed so far. In the meantime, we look forward to having a chance to run the Chrysler hybrids against their GM counterparts soon.