2003 Mitsubishi Diamante Sedan MPG & Specs — Real Fuel Cost
Quick answer
The 2003 Mitsubishi Diamante Sedan gets an EPA-estimated 16/23 MPG (city/highway) and 18 MPG combined, with an estimated $4,200/year fuel cost and 493.722 g/mi CO₂. Engine: 3.5 L 6-cyl.
The 2003 Mitsubishi Diamante Sedan with the 3.5-liter 6-cylinder premium gasoline engine returns an EPA-estimated 16 MPG in the city and 23 MPG on the highway, for a combined 18 MPG. This page summarizes the official EPA fuel-economy and emissions data for this configuration.
| Engine | 3.5 L 6-cyl |
| Transmission | Automatic 4-spd |
| Drive | Front-Wheel Drive |
| Fuel type | Premium Gasoline |
| Vehicle class | Midsize Cars |
| MPG — city | 16 |
| MPG — highway | 23 |
| MPG — combined | 18 |
| Annual fuel cost* | $4,200 |
| CO₂ tailpipe | 493.722 g/mi |
| EPA GHG score | — |
How efficient is it?
With a combined 18 MPG, the 2003 Mitsubishi Diamante Sedan sits in the low range for fuel economy. That is roughly 29% thirstier than the typical Midsize Cars of its era (26 MPG class average) — expect higher fuel bills than class-average alternatives.
Fuel economy and running costs
At about $4,200 per year in fuel (EPA estimate, 15,000 mi/yr), fuel is a major part of the cost of owning the 2003 Mitsubishi Diamante Sedan. Over five years that is roughly $21,000 at today's prices — before insurance, maintenance, and depreciation.
Emissions
The 2003 Mitsubishi Diamante Sedan emits approximately 493.722 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.