The Chrysler Aspen and Dodge Durango were similar body-on-frame SUVs; the Aspen came late in the Durango's run, and was quickly dropped. A hybrid-electric version of both SUVs was launched in 2008 for the 2009 model year — but the last Aspen was made at the end of 2008, making its run short indeed.
The hybrid-electric powerplant had been developed along by GM (the leader), BMW, and Chrysler, whose version used a Hemi V8 and boosted gas mileage by 40% in the city cycle, for an overall 25% gain. One could average 20 mpg around town, a far cry from the EPA's estimate of 13 mpg city, 18 mpg highway, for the stock Chrysler Aspen Hemi with four wheel drive.
The system replaced the usual automatic transmission with a shell of similar size and shape, containing a continuously variable transmission for two electric motors and with four mechanical gear ratios for the V8 engine. This would, in theory, let automakers easily adapt it for any car or truck that used that transmission; so, had fuel prices kept rising, Dodge could have added the setup to Ram pickups and Jeep could have used it in the Grand Cherokee. Instead, the economy crashed and fuel prices fell quickly, aided by increased domestic production shortly afterwards as fracking came of age.
The Durango / Aspen Hybrid was powered by the electric motors, the Hemi, or a combination of both. The electric motors had regenerative braking (generating power from braking) for efficiency. The standard variable-cam Hemi was good for 365 horsepower and 390 lb-ft of torque; the hybrid got a 345 horsepower version, though the motors boosted the combined system to 385 horsepower.
One may ask, “Why make a hybrid with a V8?” The answer is in the Hemi's ability to shut off half its pistons, so that it could run on four-cylinder mode; the V6 and 4.7 V8 could not do that, and in any case were not as efficient. The electric motors helped reduce the load on the Hemi so it stayed in four-cylinder mode more often. The downside was that drivers with heavy feet could easily get poor mileage, and we found it didn't take much to get a Chrysler Aspen Hybrid down to 16 mpg (about the same as the contemporary V6 Ford Flex, though the Ford had only 4,000 pounds of towing capacity). The Durango was still rated at 6,000 pounds.
The use of high and low speed electric transmission modes led to the label “two-mode hybrid.”
In the first mode (light loads and low speeds), it could work as pure electric, pure gasoline, or a combination; the second mode was a combination. The automatic worked normally, with the motors' torque adjusted via the CVT. The 300-volt battery pack was arranged so that passenger space wasn't changed. To compensate for the added cost of the hybrid powerplant, Chrysler threw masses of standard features at the Durangos and Aspens that had them.
Inside, the car was little different from gasoline versions, except that:
In addition, when the ignition switch was put onto Run, a green READY light came up instead of the engine starting. The engine came on when needed without any jarring, and shut off again subtly. At lights the engine usually shut off, instantly restarting as needed (the hybrid system also acted as a starter). Like the “four-eight” engine, it was there when needed, but not obvious.
The system provided quick acceleration from any speed, though, on the highway, the feeling of power was less pronounced than with the lower-power gasoline Hemi. This may have been due to smoothing of the power transmission through the transmission.
All of the Hemi Hybrids had an automatic all wheel drive system. When going downhill, the Aspen generated power for its batteries, causing more drag than an automatic transmission would, which may have been odd for those used to conventional automatics but was normal for anyone used to a manual transmission.
The extra weight of the motors and battery pack were handled in stride, without any substantial effect on cornering or feel; if anything, the road feel was smoother than with the standard cars, likely due to the extra weight.
The Aspen had three rows of seats; with the rearmost seat folded, Chrysler claimed more cargo room than the Chevy Tahoe, Ford Expedition, Nissan Armada, or Toyota Sequoia, with 48 inches between the wheelhouses. Both rear rows of seats folded flat, with a 2/3 split in back and a 2/1/2 split in the middle row. None of the seats seemed to be padded.
The standard 2009 Chrysler Aspen Limited AWD started at $34,490, before discounts and rebates, which included the 4.7 V8 engine, four-speaker CD, power driver's seat, a huge array of safety features, and many conveniences. Our 2007 model with the Hemi engine cost $43,150, including numerous options; our hybrid test car, with more standard features, tipped the scales at $46,420, including a single option, the power sunroof, at $850. The base price of the Aspen Limited Hybrid, was $45,570, including destination — cheaper than the Chevrolet Suburban hybrid but far above a typical Durango. .
The Chrysler Aspen Hybrid's standard features included side curtain airbags for every row, ABS, rear wiper/washer, cruise, power adjusted pedals, backup alert, rear camera, rear-seat DVD/satellite TV screens and player, navigation with traffic, DVD and hard-drive eight-Alpine-speaker stereo with a subwoofer and steering-wheel controls, heated front seats, rear air conditioning and heater, dual-zone automatic front climate control, cellphone control, rear defroster, wheelLED lighting, full-sized spare, fog lights, heated power mirrors, driver memory (seats, radio, pedals, mirrors, climate control), and chrome-clad aluminum wheels. It was a very well equipped vehicle — but at that price, it needed to be.
The Durango Hybrid and Aspen Hybrid were essentially a good idea. Every car using the same transmission — Durango, Aspen, Ram, Grand Cherokee, and Commander — could get a hybrid version with little development costs. However, the system was still expensive, especially for the benefit, and a setup specifically for the Durango would likely be more efficient.
Had fuel costs continued to climb, it's likely that Chrysler and GM would have used the hybrid system on numerous trucks, amortizing development costs and perhaps bringing the entire system cost down — but fuel prices plummeted, along with Durango and Aspen sales, and the system disappeared from Chrysler's arsenal.
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