2008 Mercedes-Benz GL320 CDI 4matic MPG & Specs — Real Fuel Cost
Quick answer
The 2008 Mercedes-Benz GL320 CDI 4matic gets an EPA-estimated 18/24 MPG (city/highway) and 20 MPG combined, with an estimated $4,000/year fuel cost and 509 g/mi CO₂. Engine: 3 L 6-cyl.
The 2008 Mercedes-Benz GL320 CDI 4matic with the 3-liter 6-cylinder diesel engine returns an EPA-estimated 18 MPG in the city and 24 MPG on the highway, for a combined 20 MPG. This page summarizes the official EPA fuel-economy and emissions data for this configuration.
| Engine | 3 L 6-cyl |
| Transmission | Automatic 7-spd |
| Drive | 4-Wheel or All-Wheel Drive |
| Fuel type | Diesel |
| Vehicle class | Sport Utility Vehicle - 4WD |
| MPG — city | 18 |
| MPG — highway | 24 |
| MPG — combined | 20 |
| Annual fuel cost* | $4,000 |
| CO₂ tailpipe | 509 g/mi |
| EPA GHG score | — |
How efficient is it?
With a combined 20 MPG, the 2008 Mercedes-Benz GL320 CDI 4matic sits in the moderate range for fuel economy. That is about 16% better than the typical Sport Utility Vehicle - 4WD of its era (17 MPG class average), making it one of the more efficient choices in its class.
Fuel economy and running costs
At about $4,000 per year in fuel (EPA estimate, 15,000 mi/yr), fuel is a major part of the cost of owning the 2008 Mercedes-Benz GL320 CDI 4matic. Over five years that is roughly $20,000 at today's prices — before insurance, maintenance, and depreciation.
Emissions
The 2008 Mercedes-Benz GL320 CDI 4matic emits approximately 509 grams of CO₂ per mile at the tailpipe. Lower emissions generally track higher fuel economy.
How to read these numbers
EPA figures come from standardized laboratory test cycles and are the same estimates shown on the vehicle's window sticker. Your real-world mileage depends on driving style, conditions, fuel grade, and maintenance. Use combined MPG and annual fuel cost to compare vehicles fairly.