2008 Mercedes-Benz R320 CDI 4matic MPG & Specs — Real-World vs EPA, All Trims
Fuel grade varies by trim — see the breakdown below.
Is the 2008 Mercedes-Benz R320 CDI 4matic good on gas?
At up to 21 MPG combined, the 2008 Mercedes-Benz R320 CDI 4matic is better than average for a Sport Utility Vehicle - 4WD — that class averages about 17.3 MPG across 2,078 EPA-tested versions, so it's a good pick on fuel for its size.
Real-world MPG vs the EPA number
The EPA figures above come from a standardized dynamometer test, not the open road — real-world MPG typically runs a bit lower depending on your driving, climate and terrain. That's true of every car on this site, old or new.
At today's AAA national average price — $4.78/gal for diesel gas as of 2026-07-05 — the most efficient trim runs about $3,414/year (roughly $284/month, about $22.76 per 100 miles) at the EPA's assumed 15,000 miles/year, using an estimated 714 gallons a year. We don't estimate a cost-per-fill since exact tank size isn't in the public EPA dataset, but the per-100-mile figure scales to any tank. Current national average gas prices →
2008 Mercedes-Benz R320 CDI 4matic trims & fuel economy
| Trim (engine / transmission) | Fuel | MPG | Fuel/yr (today's price) |
|---|---|---|---|
| 3.0L 6-cyl, Automatic 7-spd, AWD | DIESEL | 21 | $3,414 |
2008 Mercedes-Benz R320 CDI 4matic specs
What the EPA test-car listings record for this model year — every combination sold is a row in the trims table above.
| Engine options | 3.0L 6-cyl turbo |
| Transmission | Automatic 7-spd |
| Drive type | AWD |
| EPA body class | Sport Utility Vehicle - 4WD |
| Fuel | Diesel |
Other years of the Mercedes-Benz R320 CDI 4matic
Similar cars (Sport Utility Vehicle - 4WD)
Cars that take premium · Cheapest cars to fuel · Where fuel grade depends on the trim · Fuel guides
1 trim(s) · EPA FuelEconomy.gov data retrieved 2026-07-24 · fuel prices AAA national average as of 2026-07-05.