- Newest year: 2004
- Gas
- Small cars
- Same as 2003
2003-2004 Infiniti M45 MPG & Fuel Cost
2 model years · 18 MPG combined
15,000 mi/yr · premium gasoline $5.36/gal (U.S. average, Sep 2026)
Cheaper to fuel than 1 of 10 small car configurations, MY2004. Ranked against all rated configurations, not sales-weighted.
2003-2004 Infiniti M45 at a glance
The 2003-2004 Infiniti M45 covers 2 model years in the EPA database (2 configurations in all), rated 18 MPG combined. The newest model year, 2004, costs about $4,460 a year to fuel for its most efficient version, the M45 4.5L 8-cyl RWD (18 MPG), at premium gasoline $5.36/gal (U.S. average, Sep 2026). EPA lists identical ratings for every model year of this generation.
EPA re-estimated ratings of 1985-2007 vehicles under its 2008 method; these figures are the re-estimated values.
2003-2004 Infiniti M45 by model year
What the 2004 M45 4.5L 8-cyl RWD costs to drive
Per month
$372
$4,460 a year ÷ 12
Per 25 miles
$7.43
Per 100 miles
$29.73
Five years
$22,300
5 × the yearly cost, prices held at today's level
vs the small car median
$810more a year
Class median $3,650 a year, MY2004
Based on 15,000 miles a year and premium gasoline $5.36/gal (U.S. average, Sep 2026).
2004 Infiniti M45 MPG
EPA re-estimated ratings of 1985-2007 vehicles under its 2008 method; these figures are the re-estimated values.
EPA lists the same ratings for the 2004 Infiniti M45 as for the 2003 model, so the configurations and costs are the ones in the 2003 section above.See 2003
Gas configurations (1)
| Trim | Engine | Drive | City | Hwy | Comb. | $/yr |
|---|---|---|---|---|---|---|
| M45 (Most efficient) | 4.5L 8-cyl | RWD | 16 | 22 | 18 | $4,460 |
1 configuration requires or recommends higher-octane gasoline and is costed at premium gasoline $5.36/gal (U.S. average, Sep 2026).
2003 Infiniti M45 MPG
18 MPG · $4,460/yr
EPA re-estimated ratings of 1985-2007 vehicles under its 2008 method; these figures are the re-estimated values.
Gas configurations (1)
| Trim | Engine | Drive | City | Hwy | Comb. | $/yr |
|---|---|---|---|---|---|---|
| M45 (Most efficient) | 4.5L 8-cyl | RWD | 16 | 22 | 18 | $4,460 |
1 configuration requires or recommends higher-octane gasoline and is costed at premium gasoline $5.36/gal (U.S. average, Sep 2026).
Fuel cost by state
Yearly cost of the M45 4.5L 8-cyl RWD: $5,320 in California and $3,870 in Texas, a $1,450 difference.
- California $5,320
- Washington $5,010
- New York $4,410
- Florida $4,080
- Texas $3,870
Similar cars
Closest combined MPG among MY2004 small car models.
Generations
- 2003-2004 (2nd gen)
- 2006-2010 (3rd gen)
Frequently asked questions
What gas mileage does the 2003-2004 Infiniti M45 get?
EPA rates the 2003-2004 Infiniti M45 at 18 MPG combined across 2 configurations and 2 model years. The most efficient version, the 2004 M45 4.5L 8-cyl RWD, is rated 18 MPG (16 city, 22 highway).
Which years had the best MPG in the 2003-2004 Infiniti M45?
Every model year of the 2003-2004 Infiniti M45 tops out at 18 MPG combined, so no year is better than another.
Did EPA ratings change during the 2003-2004 Infiniti M45?
No. EPA lists the same ratings for every model year from 2003 to 2004.
How much does it cost to fuel a 2004 Infiniti M45 per year?
Driving 15,000 miles a year at premium gasoline $5.36/gal (U.S. average, Sep 2026), the M45 4.5L 8-cyl RWD costs about $4,460 a year. Across all 1 configuration the cost runs $4,460 a year.
How much does it cost to drive a 2004 Infiniti M45 100 miles?
About $29.73 per 100 miles for the M45 4.5L 8-cyl RWD at premium gasoline $5.36/gal (U.S. average, Sep 2026). That is the annual cost over 15,000 miles divided by 150.
Is the 2004 Infiniti M45 more efficient in the city or on the highway?
The M45 4.5L 8-cyl RWD is rated 16 city and 22 highway MPG, so it is more efficient on the highway, by 6 MPG.
How does the 2004 Infiniti M45 compare with other small car configurations?
The M45 4.5L 8-cyl RWD costs about $4,460 a year to fuel, $810 more than the class median of $3,650, and less than 1 of 10 small car configurations. The comparison covers all 356 rated small car configurations for MY2004, not weighted by sales.
Is the 2004 Infiniti M45 different from the 2003 model?
No. EPA lists the same ratings for 2003 and 2004: 1 configuration rated 18 MPG combined. See the 2003 Infiniti M45 for that year.