Best Performing Fuels: Gasoline, Diesel, Electric, Hydrogen, CNG

Priscilla ValdezMay 20, 2022

Alternative fuels are on the top of many fleet managers’ minds these days. Fleets are increasingly exploring new ways to get the job done while remaining operationally efficient, cost effective and sustainable.

As a result, many managers are introducing a mix of electric, hydrogen, and natural gas-powered vehicles into their fleets to work alongside traditional gas and diesel ICEVs. Other managers might be more apprehensive to take the leap into unchartered territory, especially if it risks compromising fleet efficiency.

To compare different fuels, we can look at their gasoline gallon equivalent (GGE). This is the amount of fuel needed to equal the same amount of energy contained in one gallon of gasoline. Something to keep in mind, however, is that fuels have varying efficiency and experience loss of energy from the point of fueling to powering the vehicle in motion.

Costs are based on national average prices as of May 2022.

Let’s discuss about how these different fuels perform in terms of GGE, operational efficiency and cost.

Gasoline and diesel

Gas and diesel are the most commonly used fuels across the board. They have numerous applications in all types of vehicles and machinery from cars to aircrafts to construction equipment.

In terms of fuel efficiency, diesel has a higher energy density containing about 15 percent more energy than gasoline. It is also a much thicker fuel, making it slower to evaporate within the tank. In a direct comparison, 1 gallon of diesel contains the same amount of energy as 1.12 gallons of gasoline.

Though fuel economy ranges widely from vehicle to vehicle, the average diesel car would need around 2.94 gallons of diesel to drive 100 miles, costing about $16.35 accounting for today’s record high fuel prices. In comparison, the average gasoline car would require around 3.89 gallons, costing $17.77.

For fleet managers, diesel’s higher price is something that could offset the better fuel economy of diesel vehicles. However, with a diesel engine having fewer components, one would also have to consider the fewer maintenance costs associated with a diesel-powered vehicle.


As the world slowly but surely moves toward electric vehicles, electricity is becoming another prominent fuel option for fleets. The EV market depends on lithium-ion batteries which store energy within vehicles and determine the vehicles’ capacity and range. While these batteries are extremely efficient at storing energy, over time their performance can be affected by battery degradation, extreme temperatures and phantom drain.

Unlike gas and diesel, electricity cannot be measured in gallons. Instead, electricity is measured in kilowatt hours (kWh), with each kWh corresponding with .03 gallons of gasoline equivalent. On average, an EV requires about 30 kWh to reach 100 miles worth of charge. Considering average electricity prices in the US today, this would cost a little over $3.

Electric vehicles are also far more efficient than internal combustion engine vehicles, with EVs converting around 80 percent of energy to power at the wheels compared to around 20 percent for ICEVs.


One alternative fuel that has piqued the interest of many automakers looking to invest into cutting edge sustainability solutions is hydrogen. As one of the most abundant elements on earth, hydrogen has major potential as a sustainable fossil fuel alternative.

Fuel cell electric vehicles (FCEVs) work similarly to battery electric vehicles with an electric motor and no internal combustion engine. However, they use a propulsion system that converts hydrogen into electricity to power the motor.

Hydrogen is measured in pounds or kilograms, with each gallon of gasoline equating one kilogram of hydrogen. Depending on the vehicle, FCEVs need about 1.6kg of hydrogen to run 100 miles costing around $26.42.

In addition to a lack of vehicle options available today, a major barrier to FCEV adoption is their operational inefficiency. When it comes to power-to-vehicle-drive, around 60 percent of total energy is lost by the time the car is in drive. This occurs because energy must be transferred from wire to gas and back into electricity, with each transition taking a toll on the energy ultimately available for use.

While this sounds like a dealbreaker for hydrogen vehicles, it is helpful to remember the lower energy efficiencies of gasoline and diesel.


Compressed natural gas has been used for decades and is ideal for converting medium- to heavy-duty ICEVs to be more sustainable. CNG is a fossil fuel just like gasoline and diesel, but it is considered the cleanest of the bunch which makes it an attractive option for fleets.

At the pump, CNG is typically sold in gallons of gasoline equivalent (GGE) with each GGE equaling 5.66 pounds of CNG. Fueling takes the same amount of time as with gas and diesel, but the compressed natural gas is stored in a high-pressure cylinder aboard instead of within a fuel tank.

To drive 100 miles in a CNG vehicle, it would take about 2.33 GGE, making CNG more efficient than both gasoline and diesel. National average prices of CNG are just above $2 per GGE today, so 100 miles worth of fuel would cost about $5.80. As a domestically produced fuel, another noteworthy benefit for fleet managers is the stability in CNG’s price. All things considered, CNG is great option for fleets looking to improve on sustainability and cut costs without having to completely overturn their fleet.

Bottom line

Having discussed and compared these top fuels and how they perform, it is clear to see that each comes with their own list of pros and cons. Ultimately, the right fit comes down to a fleets’ individual needs and goals as well as their budget and priorities. For fleets prioritizing sustainability and emissions reduction, EVs seem like a no-brainer. However, for fleets with heavy-duty trucks who don’t have EV options available, a fuel like CNG can be an excellent short-term solution until the EV market expands its offerings.

READ MORE: Will CNG be a Stop-Gap Solution to the EV Shortage?

Regardless, it is worth taking a closer look at your fleet’s vehicle and fuel mix to see if changes could be made in any areas. Luckily, technology is constantly advancing which can mean better fuel efficiency in newer vehicles and less loss of energy throughout the wells-to-wheel fuel cycle.

If you’re interested in finding out about other sustainability solutions for your fleet, schedule a demo 
with a member of our analytics team today.

Priscilla Valdez

Content Specialist

Priscilla Valdez is a content specialist at Utilimarc. She enjoys storytelling and sharing industry insights through writing that is compelling and dynamic. See more from Priscilla

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