2004 Pontiac Bonneville (3.8L 6-cyl, Premium) MPG & Specs
Quick answer
The 2004 Pontiac Bonneville gets an EPA-estimated 16/26 MPG (city/highway) and 20 MPG combined, with an estimated $3,800/year fuel cost and 444.35 g/mi CO₂. Engine: 3.8 L 6-cyl.
The 2004 Pontiac Bonneville with the 3.8-liter 6-cylinder premium gasoline engine returns an EPA-estimated 16 MPG in the city and 26 MPG on the highway, for a combined 20 MPG. This page summarizes the official EPA fuel-economy and emissions data for this configuration.
| Engine | 3.8 L 6-cyl |
| Transmission | Automatic 4-spd |
| Drive | Front-Wheel Drive |
| Fuel type | Premium Gasoline |
| Vehicle class | Large Cars |
| MPG — city | 16 |
| MPG — highway | 26 |
| MPG — combined | 20 |
| Annual fuel cost* | $3,800 |
| CO₂ tailpipe | 444.35 g/mi |
| EPA GHG score | — |
How efficient is it?
With a combined 20 MPG, the 2004 Pontiac Bonneville sits in the moderate range for fuel economy. That is roughly 24% thirstier than the typical Large Cars of its era (26 MPG class average) — expect higher fuel bills than class-average alternatives.
Fuel economy and running costs
At about $3,800 per year in fuel (EPA estimate, 15,000 mi/yr), fuel is a major part of the cost of owning the 2004 Pontiac Bonneville. Over five years that is roughly $19,000 at today's prices — before insurance, maintenance, and depreciation.
Emissions
The 2004 Pontiac Bonneville emits approximately 444.35 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.