Highlights:

  • National fuel efficiency is up 11.2 percent, with 1- to 5-year-old cars averaging 27.5 MPG in 2024 compared to 24.8 in 2019
  • At the state level, Arkansas, Washington, and California saw the biggest improvements in average MPG between 2019 and 2024, up 31.7, 21.9, and 19.4 percent, respectively
  • Arkansas also led in combined hybrid and electric vehicle market share growth, rising 875.4 percent, followed by Louisiana (299.1 percent) and New Jersey (285.8 percent)
  • South Carolina, Rhode Island, and North Dakota had the smallest improvements in MPG while also showing some of the smallest improvements hybrid and electric vehicle sales
  • Hawaii, Michigan, and South Carolina had the lowest growth in combined hybrid and electric vehicle sales, though even these states more than doubled their hybrid/EV share between 2019 and 2024
  • While hybrid sales are rising in every state, the overall hybrid segment’s MPG is dropping due to an increasing percentage of hybrid truck and SUV sales

The fuel efficiency of America’s cars continues to improve due to higher MPG ratings for late-model internal combustion models along with increasing sales of hybrid and electric vehicles.. Much of this is driven by government regulations, but consumers are also looking to spend less to fuel their cars, which gives fuel efficient models an advantage in the market.

While the fuel efficiency for 1- to 5-year-old models is up 11.2 percent nationally, not all states are contributing equally. Arkansas led the nation in both growing its MPG figures and increasing its hybrid and electric vehicle market share. The state has experienced a 31.7 percent improvement in fuel efficiency since 2019, from 22.8 MPG to 30.1 MPG. Arkansas’ combined hybrid and electric vehicle market share ballooned from 0.9 percent to 8.9 percent, an impressive 875 percent growth rate that clearly contributed to the state’s top rank in rising fuel efficiency. 

iSeeCars analyzed over 19 million 1- to 5-year-old cars sold in 2019 and 2024, both nationally and by state, to compare average MPGs and calculate the 5-year change in market share of hybrid and electric vehicles.  

“States like California and Washington are known for their efforts to improve fuel economy and reduce emissions, so it’s not surprising to see them rank well in this area,” said Karl Brauer, iSeeCars Executive Analyst. “But seeing Arkansas outrank both states in the areas of rising fuel efficiency and growing hybrid and EV market share was something we couldn’t have predicted. Arkansas ranks among the top five states for growth in hybrid, plug-in hybrid, and EV categories, showing rapid adoption across a broad spectrum of fuel-efficient vehicle types.”

 

The Best States for MPG and Hybrid/Electric Vehicle Growth

Washington state ranked second for improved MPG figures at 21.9 percent growth, with California coming in third at 19.4 percent. 

“Unlike Arkansas, Washington and California were already above the national MPG average in 2019, making their high growth over the last five years more challenging and even more impressive,” said Brauer.

Top 10 States With the Largest Improvement in Average MPG: 2019-2024 - iSeeCars Study
Rank State Avg MPG 2024 Avg MPG 2019 % Change Green Vehicle Share 2024
1 Arkansas 30.1 22.8 31.7% 8.9%
2 Washington 31.7 26.0 21.9% 12.3%
3 California 33.5 28.1 19.4% 14.4%
4 Maryland 29.8 25.2 18.2% 9.0%
5 Nevada 29.6 25.6 15.7% 8.8%
6 Utah 28.9 25.0 15.7% 9.1%
7 Virginia 28.7 24.9 15.4% 7.8%
8 Vermont 28.0 24.3 14.9% 7.5%
9 Oregon 29.5 26.1 12.8% 10.2%
10 Oklahoma 26.1 23.2 12.8% 3.9%
National Average 27.5 24.8 11.2% 6.4%
For combined hybrid and electric vehicle market share, Louisiana ranked second in growth rate with a 299 percent improvement since 2019. It was followed by New Jersey with a 286 percent growth rate and West Virginia with 281 percent growth. 
Top 10 States with the Largest Growth in Hybrid/EV Adoption, 2019-2024 - iSeeCars Study
Rank State % Share 2024 % Share 2019 % Change
1 Arkansas 8.9% 0.9% 875.4%
2 Louisiana 2.9% 0.7% 299.1%
3 New Jersey 5.8% 1.5% 285.8%
4 West Virginia 3.2% 0.8% 280.6%
5 Maryland 9.0% 2.4% 268.8%
6 North Dakota 2.9% 0.8% 267.9%
7 Montana 3.8% 1.1% 254.4%
8 Wyoming 2.9% 0.8% 247.2%
9 Minnesota 6.3% 1.8% 243.2%
10 Maine 5.6% 1.7% 225.5%
National Average 6.4% 2.3% 172.9%

The Worst States for MPG and Hybrid/Electric Vehicle Growth

ed by South Carolina, Rhode Island, and North Dakota, these 10 states had the smallest MPG improvements over the past five years. South Carolina bumped its average from 24.4 to 25.4 MPG and Rhode Island increased from 25.4 to 26.5 MPG. Both states saw 4.1 percent MPG growth, with third-ranked North Dakota doing a bit better at 5.5 percent growth, from 21.4 to 22.6 MPG between 2019 and 2024.
Top 10 States With the Smallest Improvement in Average MPG: 2019-2024 - iSeeCars Study
Rank State Avg MPG 2024 Avg MPG 2019 % Change Green Vehicle Share 2024
1 South Carolina 25.4 24.4 4.1% 3.6%
2 Rhode Island 26.5 25.4 4.1% 5.1%
3 North Dakota 22.6 21.4 5.5% 2.9%
4 South Dakota 23.1 21.8 5.6% 2.7%
5 Mississippi 24.8 23.5 5.7% 2.7%
6 Wyoming 22.7 21.4 5.8% 2.9%
7 Alabama 25.5 24.1 6.0% 3.6%
8 New Hampshire 26.0 24.6 6.0% 5.0%
9 Kentucky 25.3 23.7 6.5% 4.1%
10 Iowa 24.3 22.8 6.6% 4.1%
National Average 27.5 24.8 11.2% 6.4%
“All 10 of these states were below the national average for MPG in 2019, except Rhode Island,” said Brauer. “America’s smallest state managed to slip from being above the national MPG average to below it over the past five years.”

When ranking states with the lowest change in hybrid and electric vehicle adoption since 2019, California and Oregon are in the top 10. Both states had substantially more of these vehicles than the national average five years ago, reflecting the difficulty in maintaining an aggressive hybrid and EV growth rate after getting above an 8 percent to 10 percent share.

Top 10 States With the Least Growth in Green Vehicle Adoption: 2019-2024 - iSeeCars Study
Rank State % Share 2024 % Share 2019 % Change
1 Hawaii 6.5% 3.2% 103.3%
2 Michigan 3.7% 1.7% 113.2%
3 South Carolina 3.6% 1.7% 116.7%
4 Oregon 10.2% 4.6% 123.6%
5 California 14.4% 6.3% 129.4%
6 New Mexico 4.9% 2.1% 140.6%
7 Arizona 7.9% 3.2% 144.6%
8 Alaska 4.8% 1.9% 152.7%
9 Kansas 5.1% 2.0% 156.6%
10 Ohio 4.5% 1.7% 158.8%
National Average 6.4% 2.3% 172.9%
“Many of the states on this list simply don’t show strong demand for hybrid and electric vehicles, as evidenced by their below-average share for these models in both 2019 and 2024,” said Brauer.

 

The Best and Worst States for Electric Vehicle Adoption

Looking at pure electric vehicle adoption over the past five years reflects massive growth, with the top 10 states increasing more than twice as fast as the national average. West Virginia had too few EVs in 2019 to record, making it impossible to calculate its growth rate. Arkansas again shows rapid alternative fuel vehicle growth, with a 13,950 percent increase in EV market share from 0 percent to 5.6 percent since 2019.
Top 10 States With the Largest Growth in Electric Vehicle Adoption: 2019-2024 - iSeeCars Study
Rank State % Share 2024 % Share 2019 % Change
1 West Virginia 0.3% 0.0%* --*
2 Arkansas 5.6% 0.0% 13950.3%
3 Louisiana 0.8% 0.0% 2915.6%
4 New Jersey 2.6% 0.1% 1843.2%
5 Maryland 4.0% 0.2% 1839.8%
6 Missouri 2.1% 0.1% 1789.5%
7 Alaska 0.8% 0.0% 1651.0%
8 Montana 0.4% 0.0% 1589.6%
9 Delaware 1.3% 0.1% 1574.5%
10 Virginia 3.2% 0.2% 1532.2%
National Average 2.5% 0.3% 724.1%
*West Virginia's ysed EV share was too low to measure in 2019

Many of the states with the smallest growth in electric vehicle adoption also had relatively high EV market share five years ago, including Hawaii, Oregon, Arizona, Washington, and Colorado. This suggests increased resistance to growing EV market share in a local market once it reaches a given level.

Top 10 States With the Least Growth in Electric Vehicle Adoption: 2019-2024 - iSeeCars Study
Rank State % Share 2024 % Share 2019 % Change
1 South Carolina 0.7% 0.2% 212.3%
2 Hawaii 3.2% 1.0% 225.9%
3 Oregon 3.6% 1.0% 250.1%
4 Idaho 1.2% 0.3% 284.6%
5 Rhode Island 1.3% 0.3% 368.4%
6 Arizona 3.6% 0.7% 391.7%
7 Wyoming 0.3% 0.1% 419.7%
8 Washington 6.0% 1.1% 443.1%
9 Colorado 2.8% 0.5% 444.2%
10 Nebraska 0.9% 0.2% 468.7%
National Average 2.5% 0.3% 724.1%
“It’s worth noting California didn’t make the top 10, ranking 14th for the smallest growth in EV adoption over the past five years,” said Brauer. “The Golden State went from 0.9 percent EV share in 2019 to 6.6 percent share in 2024. That’s an increase of 606.8%, which is impressive given how high California’s EV share was five years ago, but it’s a growth rate that’s still below the national average for EVs.”

 

Hybrid SUVs and Trucks Are Lowering the Hybrid Segment’s MPG

While hybrid vehicle sales and market share are up in every state, the average MPG of hybrids is down. This is due to the increased sales and market share of hybrid SUVs and trucks relative to hybrid passenger cars five years ago. Nationally, hybrid SUVs increased their share within the hybrid segment from 14.3 percent to 48.5 percent. Hybrid trucks grew from 0.0 percent to 9.2 percent of the segment. Hybrid passenger cars dropped from 85.7 percent to 33.8 percent share, mirroring the trend of increased gasoline SUV and truck sales relative to car sales over the past five years.

It’s likely many of these hybrid SUV and truck sales are replacing gasoline SUVs and trucks with lower MPG ratings, so the shift to hybrids is still improving the overall MPG figures at the state and national level. States like Virginia, Delaware and California saw the smallest drop in their hybrid MPG numbers between 2019 and 2024.

Top 10 States With the Smallest Drop in Average MPG of Hybrid Vehicles:, 2019-2024 - iSeeCars Study
Rank State Avg MPG 2024 Avg MPG 2019 % Change
1 Virginia 40.6 41.9 -3.0%
2 Delaware 39.8 41.3 -3.8%
3 California 42.1 43.9 -4.0%
4 Connecticut 39.7 41.5 -4.3%
5 Massachusetts 39.8 41.6 -4.3%
6 Maryland 40.0 41.9 -4.4%
7 New Jersey 39.7 41.6 -4.4%
8 Washington 40.6 42.6 -4.8%
9 Pennsylvania 39.4 41.5 -4.9%
10 Illinois 39.5 41.6 -4.9%
National Average 39.9 42.6 -6.3%
“The states with the biggest drop in hybrid MPG ratings are also states where utility vehicles would be the most desirable,” said Brauer. “Alaska, Montana, Wyoming and North Dakota are SUV- and truck-heavy states, so it’s easy to imagine the growth of hybrid models in the past five years skewed heavily toward trucks and SUVs in these states.”
Top 10 States With the Largest Drop in Average MPG of Hybrid Vehicles: 2019-2024 - iSeeCars Study
Rank State Avg MPG Hybrid 2024 Avg MPG Hybrid 2019 % Change Hybrid MPG 2019 – 2024
1 Alaska 36.6 43.5 -15.9%
2 Montana 36.6 42.3 -13.5%
3 Wyoming 36.0 41.3 -13.0%
4 North Dakota 36.8 41.6 -11.6%
5 Maine 38.9 43.3 -10.1%
6 Mississippi 38.6 42.8 -9.8%
7 Idaho 38.4 42.2 -8.9%
8 Michigan 38.6 42.3 -8.7%
9 Louisiana 38.7 42.4 -8.7%
10 Alabama 38.9 42.5 -8.5%
National Average 39.9 42.6 -6.3%
MPG figures continue to rise, driven by advances in gasoline technology, increased hybrid vehicle production, and the rapid rollout of electric vehicles over the past five years. All three of these elements will continue to play a role in rising MPG figures for the foreseeable future. However, how much of a role each factor plays at the state level will be influenced by everything from local climate to geography to buyer demographics.

Changes in Average MPG for Largest Metropolitan Areas

Among the nation’s 50 largest metro areas by population, San Francisco-Oakland-San Jose, CA had the largest improvement in MPG, more than double the national average, while Greenville-Spartanburg, SC had the smallest at close to a quarter the national improvement.

 

Improvement in Average MPG for 50 Largest Metro Areas, 2019-2024 - iSeeCars Study
Rank Metro Area Avg MPG 2024 Avg MPG 2019 % Change Green Vehicle Share 2024
1 San Francisco-Oakland-San Jose, CA 36.4 28.9 25.9% 19.7%
2 Seattle-Tacoma, WA 32.8 26.5 23.5% 13.4%
3 San Diego, CA 33.9 27.8 21.9% 15.0%
4 Washington, DC (Hagerstown, MD) 30.6 25.6 19.8% 10.2%
5 Sacramento-Stockton-Modesto, CA 32.3 27.0 19.3% 13.0%
6 Los Angeles, CA 33.6 28.3 18.9% 14.1%
7 Kansas City, MO 28.0 24.0 16.6% 7.4%
8 Dallas-Ft. Worth, TX 28.2 24.3 16.3% 6.3%
9 Salt Lake City, UT 28.9 25.0 15.8% 9.0%
10 Las Vegas, NV 29.9 25.9 15.5% 8.7%
11 Austin, TX 28.5 24.8 15.1% 7.4%
12 Baltimore, MD 28.7 25.1 14.5% 7.7%
13 Oklahoma City, OK 26.6 23.3 14.3% 4.6%
14 Orlando-Daytona Beach, FL 28.5 25.2 12.8% 6.0%
15 Chicago, IL 28.0 24.9 12.5% 7.2%
16 Atlanta, GA 28.0 24.9 12.2% 6.4%
17 Fresno-Visalia, CA 29.5 26.4 11.9% 8.2%
18 Portland, OR 29.7 26.6 11.7% 10.3%
19 Phoenix, AZ 28.8 25.8 11.5% 8.1%
20 Cincinnati, OH 27.7 24.8 11.3% 6.0%
21 Philadelphia, PA 28.1 25.3 11.2% 6.2%
22 Denver, CO 27.2 24.5 11.1% 7.6%
23 Tampa-St Petersburg (Sarasota), FL 27.7 24.9 11.0% 5.8%
24 Minneapolis-St. Paul, MN 26.2 23.6 11.0% 6.6%
25 Miami-Ft. Lauderdale, FL 28.2 25.5 10.6% 5.0%
26 New York, NY 27.6 25.0 10.4% 5.6%
27 Boston, MA-Manchester, NH 27.3 24.8 9.9% 6.3%
28 Indianapolis, IN 26.6 24.2 9.8% 5.3%
29 Charlotte, NC 27.2 24.9 9.3% 5.6%
30 Houston, TX 26.3 24.1 9.0% 4.5%
31 Raleigh-Durham (Fayetteville), NC 27.1 24.9 8.7% 6.0%
32 San Antonio, TX 25.9 23.8 8.7% 4.5%
33 Jacksonville, FL 27.2 25.0 8.7% 5.1%
34 St. Louis, MO 25.6 23.6 8.4% 3.9%
35 Grand Rapids-Kalamazoo, MI 25.1 23.3 8.1% 5.0%
36 Nashville, TN 26.0 24.1 7.9% 4.6%
37 West Palm Beach-Ft. Pierce, FL 27.2 25.2 7.8% 5.0%
38 Milwaukee, WI 26.2 24.3 7.8% 5.4%
39 Greensboro-Winston Salem, NC 26.5 24.6 7.5% 4.9%
40 Albuquerque-Santa Fe, NM 26.0 24.2 7.4% 5.2%
41 Hartford & New Haven, CT 27.0 25.2 7.2% 5.4%
42 Louisville, KY 25.7 24.0 7.2% 4.6%
43 Detroit, MI 25.5 23.8 7.1% 4.1%
44 Columbus, OH 26.7 24.9 7.0% 5.1%
45 Harrisburg-Lancaster-York, PA 26.3 24.6 6.9% 5.6%
46 Norfolk-Portsmouth-Newport News,VA 26.5 24.8 6.7% 4.6%
47 Birmingham, AL 25.9 24.4 6.2% 3.9%
48 Pittsburgh, PA 25.5 24.1 5.8% 4.1%
49 Cleveland-Akron (Canton), OH 26.4 24.9 5.7% 3.9%
50 Greenville-Spartanburg, SC 25.5 24.8 2.9% 4.3%
National Average 27.5 24.8 11.2% 6.4%

Methodology

iSeeCars analyzed over 19 million 1- to 5-year-old used cars sold between January and September of 2019 and 2024. The average MPG of these vehicles was aggregated nationally and by state and compared across the two periods. Note that MPGe was used for plug-in hybrids and electric vehicles. The share of hybrids, plug-in hybrids, and electric vehicles was also calculated and compared across the two timeframes.

 

About iSeeCars.com

iSeeCars.com is a data-driven car search and research company that helps shoppers find the best car deals by providing key insights and valuable resources, including the iSeeCars VIN Check report and Best Cars Rankings. iSeeCars has saved users over $426 million so far by applying big data analytics powered by over 25 billion (and growing) data points and using proprietary algorithms to objectively analyze, score and rank millions of new cars and used cars.