The Engine
The standard engine in the Sport is a 210hp 3.7L V-6, while a 4.7L V-8 cranking out 235 hp is standard for the Limited (optional for the Sport). That leaves a Hemi. The 5.7L V-8, which falls in as required equipment for the new Overland, is an option for the Limited. The Hemi is worth 330 hp and 375 lb-ft of torque at 4,000 rpm, and it uses Multi-Displacement System technology to shut off four cylinders when it doesn't think the extra power is needed, which saves on fuel.
A perk to owning the '07 version of the 4.7L mill is flexible-fuel capability, meaning it can run on E85, or 85 percent ethanol. That entailed tweaking of the engine's computer and the fuel tank, pump, and lines to make them able to handle their alcohol. Of course, scratch that if you're living in an ozone-hugging state - California, Maine, New York, Vermont, or Connecticut. Damn hippies.
The Transmission
The V-6 uses the W5A580 transmission, an automatic five-speed with Overdrive. It has electronic range select (ERS) or, as Jeep describes it, a driver-interactive manual control and electronically modulated torque-converter clutch. In other words, toggling the shifter from left to right to choose the tranny's top gear is supposed to help with towing and wheeling. The V-8s are hooked to the 545RFE, with three planetary gearsets, one overrunning clutch, and the same ERS system, which gives Second gear a 1.67 upshift and a 1.50 kick-down.
The Transfer Case
While three four-wheel-drive systems are used - Quadra-Trac I, Quadra-Trac II, and Quadra-Drive II - the Commander has just two transfer cases. The full-time NV140 that's standard with the 3.7L is one you won't care about because it doesn't have low range. The full-time NV245 is optional for the 3.7L, comes standard for the 4.7L and Hemi, and has 2.72 low range. For true "Trail Rated" performance, the setup would be Quadra-Drive II and the NV245 for gaining electronic limited-slips front, center, and rear.
The Suspension/The Axles
As you've probably figured out, a lot of the Commander is a do-over of the Grand Cherokee. Therefore, like the Grand, there's a short/long-arm independent front suspension with coil springs, upper and lower control arms, a stabilizer bar, and gas-charged coilover shocks. Out back is a solid axle with a track bar, a stabilizer bar, and gas-charged shocks. The front and rear axles are Corporate/AAM, and the ring-gear diameter for the front is 7.9 inches, while the rear's is 8.3 inches.
When coupled with the NV245 T-case, the 3.7L has 3.55 gears, while the V-8s run 3.73s. The maxed-out trailer weight for the 4x4 Hemi is 7,200 pounds (7,400 for the two-by), while the V-6 can haul 3,500 pounds; the 4.7L hauls 6,500 pounds. The two-wheel-drive Limited and Overland with the Hemi have a Dana 44 rear.
SPEED READING
3.7L SOHC V-6
Displacement: 226 ci
Bore x stroke: 3.66 x 3.57
Compression ratio: 9.7:1
Horsepower: 210 hp @ 5,200 rpm
Torque: 235 lb-ft @ 4,000 rpm
4.7L SOHC V-8
Displacement: 287 ci
Bore x stroke: 3.66 x 3.41
Compression ratio: 9.0:1
Horsepower: 235 hp @ 4,500 rpm
Torque: 305 lb-ft @ 3,600 rpm
5.7L HEMI V-8
Displacement: 345 ci
Bore x stroke: 3.92 x 3.58
Compression ratio: 9.6:1
Horsepower: 330 hp @ 5,000 rpm
Torque: 375 lb-ft @ 4,000 rpm
Transmission (standard): W5A580 or 545RFE
Transfer case (standard): NV140 or NV245