The large 2008 Mercedes-Benz GL320 CDI SUV equipped with the 3.0 Liter diesel was reviewed on the PBS program Motorweek this past weekend. I took a test drive back in August (here) and was impressed with this expensive and large vehicle. It certainly benefits from the diesel powerplant which will be upgraded with Urea injection later this year (reduces NOx to make it 50 state compliant). Although the overall test loop of 23mpg isn’t all that impressive, this is a big heavy full size SUV. The GL320 CDI will pull 7500 pounds and comfortably carry 7 adults - specs. The 2008 model starts at a bit over $54,000, but you’ll be hard pressed to find one without a few options which puts the price over $60,000. (If you don’t need the 3rd row seat but like the 3.0 L diesel CDI SUV, consider the Mercedes-Benz ML320 CDI which starts at $45,825 - specs)

Engine: 2,987-cc turbocharged DOHC 24-valve V-6. Aluminum block with ultra-heat-resistant aluminum cylinder heads.
Net power 215 hp @ 3,800 rpm
Net torque 398 lb-ft @ 1,600 - 2,800 rpm
Compression ratio 16.5:1
Fuel requirement
Ultra-low-sulfur diesel fuel.
Fuel tank (capacity - reserve) 26.4 gal - 3.4 gal

Fuel and ignition system: Third-generation Common-rail Direct Injection (CDI). Four valves per cylinder. Variable Nozzle Turbocharger (VNT) with electronically adjustable turbo blades. Exhaust gas recirculation with electronically controlled valve. Electronically controlled air intake throttling.

Transmission: 7-speed automatic. Steering-wheel-mounted shift buttons allow for Touch Shift gear selection. Electronically controlled shifting. Driver-adaptive programming adjusts shift points to the driver’s current driving style. Driver-selectable Comfort mode starts the vehicle moving in 2nd gear or 2nd Reverse gear, and upshifts at lower rpm to help improve control on slippery surfaces.

Drive configuration: Permanent full-time 4-wheel drive, with 50/50 front/rear torque split.

Front and rear axle ratios: 3.45:1

Off-road driving program: One-button off-road program allows driver to simultaneously engage programming recalibrations of the traction system, ABS, engine management, and automatic transmission designed to enhance control in conditions typical of off-highway driving.1

Downhill Speed Regulation (DSR): Driver-activated DSR automatically modulates the throttle, brakes, and ABS to maintain a preset crawl speed when descending hills. Speed is preprogrammed at 4 mph but may be adjusted between 3 mph and 10 mph via the multifunction steering wheel. DSR can be used when the gear selector is in Drive or Reverse. Driver can override DSR by pressing the accelerator or switching DSR off via its console-mounted switch.

Hill-start assist: To help prevent unwanted vehicle rollback when taking off from a stop on uphill or downhill grades (15 percent or over), hill-start assist automatically maintains brake pressure for approximately one second after the driver releases the brake pedal. The system is automatically deactivated when the vehicle is level, the gear selector is in Park or Neutral, or the parking brake is set.