Average MPG by Year: Fuel Economy Trends Since 1984

01 Introduction

Fuel economy is one of the most important factors in determining your annual driving cost. The EPA has tracked the fuel economy of every new vehicle sold in the United States since the 1970s, publishing its findings annually in the Automotive Trends Report. This dataset provides a comprehensive picture of how the fleet has evolved over more than four decades.

From 1984 to the present, the average fuel economy of new vehicles has risen from 19.8 MPG to over 26 MPG—a gain of roughly 33%. But that progress has been far from linear. Policy changes, consumer preferences, fuel prices, and technology shifts have all shaped the trajectory.

02 Decade-by-Decade Trends

The history of U.S. fleet fuel economy divides into three distinct eras. The first, from the late 1970s through the mid-1980s, saw rapid gains driven by the original CAFE standards enacted after the 1973 oil crisis. The second era, from roughly 1990 to 2004, was a period of stagnation as low gas prices and the rise of SUVs erased potential gains. The third era, from 2005 to the present, has seen steady improvement driven by updated CAFE standards and advancing powertrain technology.

The fleet average actually declined between 1988 and 2004, dropping from 20.6 to 19.3 MPG. This happened despite improvements in engine and vehicle technology because the market shifted heavily toward less-efficient SUVs and pickups. Only after CAFE standards were tightened beginning with Model Year 2012 did the fleet average recover and then exceed its previous high.

03 Cars vs Light Trucks

Throughout the EPA's tracking period, passenger cars have consistently achieved higher fuel economy than light trucks. As of model year 2023, passenger cars average roughly 30–31 MPG while light trucks (a category that includes SUVs, pickups, and minivans) average about 23–24 MPG. This represents a gap of approximately 7 MPG, which has remained relatively constant even as both categories improved.

The persistence of this gap means that vehicle type remains one of the strongest determinants of individual fuel cost. A driver choosing a car over a truck saves roughly $350–$500 per year in fuel at typical mileage and gas prices, depending on the specific models compared.

04 The SUV Shift and Its Impact

Perhaps the most significant trend in the EPA data is the dramatic shift in market composition. In 1984, light trucks accounted for just 28% of new vehicle sales. By 2004, that figure had crossed 50%, and by 2023 it reached approximately 60%. This shift has had a profound impact on the overall fleet average.

The EPA estimates that if the car-truck market share had remained at its 1984 levels, the fleet average fuel economy in 2023 would be approximately 2–3 MPG higher than it actually is. In other words, the shift toward SUVs and trucks has offset a meaningful portion of the technology-driven efficiency gains that manufacturers achieved during this period.

Within the light truck category, SUVs have driven most of the growth. Traditional body-on-frame SUVs and the newer crossover/unibody SUVs together now account for over 45% of all new vehicle production. Pickup trucks have maintained a relatively stable share of around 15–18%.

05 CAFE Standards and Milestones

Corporate Average Fuel Economy (CAFE) standards, administered by NHTSA, have been the primary regulatory driver of fuel economy improvement. The original CAFE standards, enacted in 1975, required passenger car fleets to reach 27.5 MPG by 1985. Light truck standards were lower and increased more slowly.

After more than two decades of largely unchanged standards, NHTSA issued updated rules beginning in 2007. The most significant update came in 2012, when NHTSA and EPA jointly finalized standards requiring the fleet to reach the equivalent of approximately 49 MPG by Model Year 2025 (measured on the EPA two-cycle test). In real-world driving, this corresponds to roughly 36–37 MPG.

Key CAFE milestones include:

• 1978: Original CAFE standards take effect for passenger cars (18 MPG target).
• 1985: Passenger car standard reaches 27.5 MPG.
• 2005–2007: First light truck CAFE increases in over a decade.
• 2012: Joint NHTSA/EPA rule sets MY 2025 target of ~49 MPG (two-cycle).
• 2022: NHTSA finalizes updated standards for MY 2024–2026.

06 What MPG Gains Mean for Your Wallet

The improvement from 19.8 MPG (1984 fleet average) to 26.4 MPG (2023 fleet average) translates to meaningful fuel savings. At 12,000 miles per year and $3.00 per gallon, a driver in a 19.8 MPG vehicle would spend approximately $1,818 on fuel, while a driver in a 26.4 MPG vehicle would spend roughly $1,364—a savings of about $455 per year.

Importantly, fuel economy improvements yield diminishing returns per MPG gained. Going from 15 to 20 MPG saves 200 gallons per year (at 12,000 miles), but going from 30 to 35 MPG saves only 57 gallons. This means that improving the efficiency of the least efficient vehicles on the road produces the greatest fuel and cost savings.

07 Data Sources

1. EPA: The 2023 EPA Automotive Trends Report, EPA-420-R-23-033. epa.gov/automotive-trends
2. NHTSA: Corporate Average Fuel Economy Standards, 49 CFR Parts 531 and 533. nhtsa.gov
3. DOE/EPA: FuelEconomy.gov – fuel economy data, tips, and comparisons. fueleconomy.gov
4. EIA: Weekly Retail Gasoline and Diesel Prices. eia.gov