Which states are the most energy-cost efficient for drivers? That depends, of course, on whether a motorist is operating a traditional gasoline-powered vehicle or an electric vehicle. Which means there are multiple answers to that question of vehicle energy-cost effectiveness, and the answers can and do change each month.

ChooseEnergy.com’s Driving Fuel Costs by State page monitors monthly costs to show you the latest statistics, trends and analysis of the costs to drive traditional vehicles and electric ones. Choose Energy analysts crunch numbers provided by AAA, the Department of Energy and other sources to measure differences by state.

Let’s start with gasoline. As of June 30, drivers in the U.S. paid an average of $2.71 per gallon for regular gasoline, according to AAA. That was 46 cents more per gallon than on Jan. 1.

Which states had the most and least expensive gasoline?

Drivers in California paid the most for their gasoline on June 30 – $3.757 per gallon. That was 22 cents less than they paid one month earlier and about 32.5 percent more than the national average. Drivers in Alabama and Mississippi paid the least per gallon on June 30 – $2.33.

Following are the 10 states where drivers paid the most and least for gasoline on June 30:

Most expensive statesJune 30 prices per gallonLeast expensive stateJune 30 price per gallon
California$3.75Alabama$2.33
Hawaii$3.64Mississippi$2.33
Washington$3.36Louisiana$2.34
Nevada$3.32Arkansas$2.36
Alaska$3.27South Carolina$2.37
Oregon$3.23Missouri$2.42
Idaho$3.01Tennesee$2.42
Utah$2.99Texas$2.42
Pennsylvania$2.92Oklahoma$2.43
Arizona$2.89Virginia$2.45

Regular gasoline prices in individual states are volatile. They fell in every state from May 31 to June 30.

The largest decrease came in Arizona, where prices fell 7.4 percent. Following are the states in which prices fell the most from May 31 to June 30:

StateJune 30 price per gallons% decrease
Arizona$2.897.4
Nebraska$2.557.3
Alaska$3.276.6
Wisconsin$2.646.4
Indiana$2.745.8
Oklahoma$2.435.8
North Dakota$2.625.8
Kansas$2.475.7
Utah$2.995.7
Idaho$3.015.6

The smallest decrease came in Hawaii, where prices fell only 0.5 percent from month to month. Following are the 10 states with the smallest percentage increases in their price per gallon as of May 31:

StateJune 30 price per gallons% decrease
Hawaii$3.640.5
West Virginia$2.701.1
North Carolina$2.561.2
Pennsylvania$2.921.7
Delaware$2.581.9
Georgia$2.541.9
Florida$2.531.9
New York$2.872.4
Wyoming$2.792.4
Maryland, Ohio$2.672.6

What are eGallons, and which states had the best prices?

The U.S. Department of Energy has developed a measure called an eGallon to compare the cost of fueling a vehicle with electricity compared with a similar vehicle that uses gasoline. The DOE calculates how much electricity the most popular electric vehicles would need to travel the same distance as similar model gasoline-powered cars. That amount of electricity is then multiplied by the average cost of electricity in the state.

So which state had the lowest eGallon price? Louisiana’s rate of $0.84 was the nation’s lowest as of June 22. The highest eGallon price was in Hawaii, at $3.09.

Following are the 10 lowest and highest eGallon prices as of June 22:

Highest priced statedPrice per eGallon (June 22)Lowest price statesPrice per eGallon (June 22)
Hawaii$3.09Louisiana$0.84
Rhode Island$2.10Washington$0.86
Alaska$2.05Missouri$0.86
Connecticut$2.05North Dakota$0.87
Massachusetts$2.03Arkansas$0.87
New Hampshire$1.83Idaho$0.88
California$1.76Oklahoma$0.88
Vermont$1.55Nebraska$0.89
New York$1.53Utah$0.93
New Jersey$1.45Kentucky$0.94

Which states are best for electric vehicle drivers?

Other than the initial cost of the purchase, every state is better for electric vehicles when comparing the cost of fueling/charging – on average, the cost is less than half for EVs. But in some states, the difference is dramatic. The widest gap between the prices for this month is in Washington, where it is $2.50.

Following is a list of the 10 states where drivers could save the most on fuel by switching to an electric vehicle:

StateGap between pricesStateGap between prices
Washington$2.50California$1.99
Oregon$2.26Montana$1.83
Nevada$2.20Wyoming$1.80
Idaho$2.13Arizona$1.77
Utah$2.06North Dakota$1.75

The state with the smallest difference between the two prices was Hawaii, where it was 55 cents.

By the numbers

Following are state-by-state numbers on the average price of gasoline per gallon of the month, the percentage above or below the U.S. average, the most recent eGallon price, and the spread between the two.

StateJune 30 price per gallons% above/below U.S. averagePrice per eGallon (June 22)Spread
Alabama$2.33-18.5$1.15$1.18
Alaska$3.2715.5$2.05$1.22
Arizona$2.892.1$1.12$1.77
Arkansas$2.36-16.6$0.87$1.49
California$3.7532.5$1.76$1.99
Colorado$2.72-3.9$1.10$1.62
Connecticut$2.861.1$2.05$0.81
Delaware$2.58-8.8$1.14$1.44
District of Columbia$2.830.0$1.24$1.59
Florida$2.53-10.6$1.08$1.45
Georgia$2.54-10.2$1.03$1.51
Hawaii$3.6428.6$3.09$0.55
Idaho$3.016.4$0.88$2.13
Illinois$2.881.8$1.17$1.71
Indiana$2.74-3.2$1.12$1.62
Iowa$2.57-9.2$1.05$1.52
Kansas$2.47-12.7$1.17$1.30
Kentucky$2.58-8.8$0.94$1.64
Louisiana$2.34-17.3$0.84$1.50
Maine$2.68-5.3$1.09$1.59
Maryland$2.67-5.7$1.22$1.45
Massachusetts$2.74-3.2$2.03$0.71
Michigan$2.79-1.4$1.38$1.41
Minnesota$2.58-8.8$1.17$1.41
Mississippi$2.33-17.7$1.05$1.28
Missouri$2.42-14.5$0.86$1.56
Montana$2.81-0.7$0.98$1.83
Nebraska$2.55-9.9$0.89$1.66
Nevada$3.3217.3$1.12$2.20
New Hampshire$2.61-7.8$1.83$0.78
New Jersey$2.80-1.1$1.45$1.35
New Mexico$2.60-8.1$1.14$1.46
New York$2.871.4$1.53$1.34
North Carolina$2.56-9.5$1.04$1.52
North Dakota$2.62-7.4$0.87$1.75
Ohio$2.66-6.0$1.11$1.55
Oklahoma$2.43-14.1$0.88$1.55
Oregon$3.2314.1$0.97$2.26
Pennsylvania$2.923.2$1.24$1.68
Rhode Island$2.73-3.5$2.10$0.63
South Carolina$2.37-16.3$1.16$1.21
South Dakota$2.69-4.9$0.97$1.72
Tennesee$2.42-14.5$0.98$1.44
Texas$2.42-14.5$1.06$1.36
Utah$2.995.7$0.93$2.06
Vermont$2.71-4.2$1.55$1.16
Virginia$2.45-13.4$1.06$1.39
Washington$3.3618.7$0.86$2.50
West Virginia$2.70-4.6$1.00$1.70
Wisconsin$2.64-6.7$1.31$1.33
Wyoming$2.79-1.4$0.99$1.80
US$2.71-4.2$1.17$1.54

Of course, having low eGallon prices does no good without a sufficient number of public charging stations. According to YourMechanic.com, California has the largest number of stations – 4,978. Which is great. But a more accurate measure may be number of people per charging station. Vermont is tops there, with a station for every 3,780 residents, while California has one for every 7,942 people.

Following are the total public charging stations for each state, the number of people per charging station, and the rank of each state by the number of people per charging station.

StateNo. of stationsPeople per charging stationRank (people per charging station)
Alabama13236,93047
Alaska982,19950
Arizona47414,80226
Arkansas10030,04345
California4,9787,9425
Colorado7307,6814
Connecticut33910,58512
Delaware4720,46737
Florida1,17317,89033
Georgia77113,52721
Hawaii2575,5552
Idaho6426,82742
Illinois81615,68928
Indiana42315,76129
Iowa3708,5028
Kansas21413,61322
Kentucky16127,66643
Louisiana11441,09148
Maine1399,61110
Maryland59210,22311
Massachusetts57611,90915
Michigan66614,95827
Minnesota6628,4247
Mississippi5851,45049
Missouri49612,32616
Montana3629,18044
Nebraska16811,42914
Nevada23612,70417
New Hampshire9713,84323
New Jersey27432,86746
New Mexico8524,56641
New York1,11517,80232
North Carolina63816,10330
North Dakota5813,02419
Ohio56620,59838
Oklahoma20718,99035
Oregon5976,9393
Pennsylvania55023,28340
Rhode Island8312,76718
South Carolina28017,94434
South Dakota1058,2836
Tennessee46814,35025
Texas1,35120,95139
Utah22413,84724
Vermont1653,7801
Virginia51216,54331
Washington8308,9239
West Virginia9519,11436
Wisconsin44013,17220
Wyoming5410,72813

By the way, we feel compelled to point out that the YourMechanic.com page referenced has a ton of good info about EVs. You should check it out, but only after you’re done here.