To make this work, we have to establish a baseline for comparison. According to the EPA, one gallon of gasoline contains exactly 33.7 kWh of raw chemical energy. That is our starting point.
But here is where the efficiency reality kicks in. Internal combustion engines are basically rolling space heaters that happen to move a car as a side hustle. They are roughly 20% efficient in the real world after braking, meaning 80% of the energy in that $3.41 gallon of gas is completely wasted as heat and noise.
Electric motors, on the other hand, are incredibly efficient. For the Fair eGallon, I use an 80% efficiency rating for EVs. You might ask why we do not use 90%, which is what an EV can achieve in stop-and-go city traffic. The answer is highway driving. When you are cruising at 75 mph, especially in a truck like my Silverado EV, you are not slowing down enough to put power back into the battery through regenerative braking.
So, 80% is the fair, real-world highway benchmark that does not overpromise or give EVs any unfair advantages. Because an EV is roughly four times as efficient (80% divided by 20%), you only need one-fourth of the raw energy to do the exact same amount of work as a gas vehicle.
When you weight the cost based on reality (90% home charging at $1.51, and 10% public charging at $4.03), you find the Real Price of an EV Fair eGallon across the board: ($1.76 per gallon)
The Fair eGallon highlights the biggest hidden advantage of driving an EV: predictability. The conversion itself doesn’t reveal this, but if you’re explaining equivalent gas prices, you have to add this important context so people don’t miss out on one of the biggest advantages.
Gasoline is highly volatile. Your monthly budget is constantly at the mercy of geopolitics. Right now, the conflict in Iran has caused a massive spike in oil prices, pushing the national average up to $3.41 and beyond. You can wake up on a Tuesday and find that your daily commute just got significantly more expensive because of a headline halfway across the world.
Electricity is entirely different. It is a regulated local utility. According to the EIA , the national average residential rate is around $0.18 per kWh right now, but that price is generally locked in for long periods. If your home rate gives you a Fair eGallon of $1.51 today, it will likely be $1.51 next month and next Christmas because utilities have to go through lengthy approval processes to hike prices.
I didn’t set out to lecture everyone on geopolitical issues or fossil fuel subsidies when I started, so let’s head back to the main point again before closing. In short, the easy way to convert electricity prices to gas prices is to multiply the electric price by about 8.4. This converts the cost of electrons to the cost of doing real-world work, and puts it in a way that people living in the fossil fuel paradigm can naturally understand whether they drive a Prius or an F350 with a 7.3L Godzilla V8.
The EPA gives us MPGe and eGallons for this, but let us be honest: MPGe is for engineers. It is technically accurate but practically useless for budgeting. Most normal people do not care about “miles per gallon equivalent” energy. They care about miles per dollar. To truly compare gas and electricity, we have to look at useful work.
