2009 Chrysler Aspen Review

Specifications

Face it. As much as large sport utility vehicles receive blame for being wasteful,unnecessary and the whipping boys of the environmental movement, they have an honest to goodness purpose in the automotive world. They’re one of the best ways of hauling large numbers of people, their stuff and most importantly their loaded trailers. Automakers are aware that shifting around thousands of pounds of machinery and humans takes energy, and that gas prices are no longer cheap, and realize that something should be done to ease the burden on SUV consumers and the environment, putting aside the fact that large sport utilities are amongst the most profitable types of vehicles for automakers to sell (that’s another story for another day). Enter the Two-Mode hybrid system, an international collaboration between General Motors, DaimlerChrysler and BMW resulting in a full hybrid powertrain that isn’t troubled by weight, stress and loads. We were lucky to get to drive an extra-early prototype of Chrysler’s variant, housed in the body of the full-size Aspen sport utility vehicle.

Both inside and outside, Chrysler’s new hybrid could pass as a normalAspen, even if you were paying attention to its finer details. The stuck-on hybrid badges were the only clues to the different nature of this large vehicle. Chrysler may introduce visual changes to the car, in the form of more aerodynamic bumpers and some other little green-oriented tidbits, although the executives who were on hand seemed pretty content in keeping such details hush-hush.

It’s also standard fare on the inside, including the standard, easy to operate console and dashboard, with the exception of one major thing. A “hybrid” gauge displaying the state of the Two-Mode system (charging, powering, etc.) has ousted the tach. The big red knob at the bottom of the console in the pictures is a safety shut-off, a device required for all testing prototypes.

Poke around the interior and there aren’t even any clues as to the whereabouts of the battery. It’s been hidden out of sight and out of mindunder the second row bench, which means that the cargo bay is as completely usable as in the normal Aspen, and there’s no loss of interior volume throughout the rest of the cabin either, something truly rare amongst hybrid vehicles.

We weren’t allowed to peek under the hood, but were assured that there was a 5.7-liter V8 with MDS cylinder deactivation beneath… basically the same mill that you’d normally find under the hood of a high-end Durango or Aspen, and yes, this hybrid’s got a Hemi. What’s more interesting is the electrical half of the equation.

Attached to the engine, and housed inside what would normally be a gearbox, are the guts of the Two-Mode hybrid system. The list of ingredients is as follows: two sets of planetary gears, plus two electric motor generators that are actuated via a pair of computer-controlled clutches. What’s so special is the way they interact, and what they’re capable of doing. The Aspen Hybrid can run on electricity, gasoline or a combination of the two, just like a true hybrid vehicle, though what’s special about the system is that you don’t feel the changes as you might in a Honda Accord Hybrid. When the electric motors are added into the equation via the planetary gears (which can be dialed in and out) the unit as a whole is able to operate like a CVT with a wide range of ratios. That’s the first mode. The second mode is primarily geared towards highway use, when the engine is always running. Here, the electric motors are bypassed, allowing torque from the engine to go straight to the wheels, cutting down on drivetrain loss and making the system, as a whole, more efficient.

This is by far the most complicated hybrid setup we’veever encountered, but then again no other hybrid system that we know of is capable of being paired with such powerful engines, and none can manage such heavy loads. Another interesting tidbit of info about the system is that there is no physical reverse gear. When reverse is selected on the column shifter, the car will always draw on its electrical motors for power. If the battery’s too low, the gasoline engine will run to charge the battery, thus enabling the car to move, similar to the e-Flex system in the Chevrolet Volt.

The Aspen and Durango Hybrids will be offered in one drivetrain configuration only, the Hemi V8 and all-wheel drive, compared to GM’s Two-Mode application in the Tahoe and Yukon which offer both AWD and RWD. Chrysler has specified this route for a specific purpose, as it enables the SUV to recapture more energy allowing it to charge the battery under braking. The crucial numbersthat everyone is focusing on – power output and fuel economy – have yet to be released, but Chrysler thinks that the Two Mode should prove much better the average overall economy of its regular Aspen by about 25-percent, a gain mostly made up in the city where it is expected to better the non-hybrid model by 40-percent. Towing and payload ratings are the same as the standard Aspen.

The smoothness that Chrysler’s engineers were able assuage out of the Two-Mode system is really quite amazing, especially given that the system hasn’t undergone much by the way of tuning. Driven regularly, the Aspen Hybrid made the transition between electric to gasoline almost unnoticeably, and as is the case with the regular 5.7-liter Hemi, the changeover of the cylinder deactivation system, between four and eight cylinders, is also unnoticeable. At speeds around 25 mph, the gasoline engine will fire up, which is a little on the low side compared to some of the hybridsedans like the Camry and Altima that we’ve driven, but at that point the electric motors have done most of the work in getting the SUV up to speed, not to mention that 40 km/h (25 mph) is often enough to cover stoplight to stoplight stints in urban areas. Also, there’s enough noise from the tires and wind to further muffle the sound of the big V8 engine, as it wakes up from its fuel-saving slumber.

Of course, there’s still quite a bit of tweaking to do. The brakes felt stiff and spongy with little in the way of feel, and the switchover between regenerative braking and plain ‘ol friction braking is fairly noticeable. These areas aside, the Aspen as a whole felt pretty natural when stacked up against the non-hybrid version. For a large SUV, I found the steering to be pretty much spot on despite the adaptation of an electrical powersteering system. This will allow the Aspen to retain fingertip-light maneuverability even when it’s running on electricity alone. One engineer admitted that the finished product could be identical to this vehicle, or it could be completely different. Thanks for the tip.

With about a year between our drive and the expected on-sale date, Chrysler is in pretty good shape for the Aspen and Durango hybrids. There are a few details that will need to be confirmed, such as pricing and exact fuel economy numbers, but we can see the system as a way of providing these full-size SUVs the boost in sales they so desperately need. And speaking of hybrid vehicles, Chrysler is also expected to bring other vehicles to market with the Two-Mode system. Though no details were discussed, we could see Dodge offering a hybrid Durango, of course, plus the Ram pickup would make a good candidate, not to mention pairing it with the upcoming series of V6 powerplants. Like many other brands, Chrysler is also interested in producing vehicles with a mild hybrid system, providing a cost-effective way for the technology to gain a critical mass in the marketplace. Add that to the widespread use of flex-fuel capable vehicles and clean diesel technology, and Chrysler’s future is looking rather green.