Measuring compressed natural gas is different than measuring petroleum-based fuels like gas and diesel. When you’re at a CNG fueling station, you may notice acronyms like GGE or DGE, and you’ll also notice that the price is based on dollar per GGE/DGE instead of gallon. If you’re not entirely familiar with CNG or how it’s measured, all of this can cause confusion. Thankfully, with a little explanation, CNG measurement can be easily understood.

The Need for Equivalents

Petroleum-based fuels and CNG are different. Gas and diesel are liquids and CNG is a gas, and this can make it difficult to compare. In order to streamline this process, the National Institute of Standards and Technology (NIST) created the standard units of measurement. Enter the DGEs and GGEs.

What are GGEs?

A GGE, or gallon of gasoline equivalent, is the most common way that CNG is sold at public fueling stations. In most cases, the CNG is priced in dollars per GGE instead of per gallon.

GGE is the amount of alternative fuel it takes to equal the energy content of one liquid gallon of gasoline. One GGE of natural gas is 126.67 cubic feet at standard conditions, and this has the same energy content as one US gallon of gasoline. When compressed to 3,600 psi, one GGE requires .51 cubic feet of space in a CNG tank. So, for example, the interior space of a 20 GGE tank is about 10 cubic feet.

What are DGEs?

DGE, or diesel gallon equivalent, is another way to measure CNG. Diesel has a higher energy content than gasoline, so diesel needs its own gallon equivalency. 1 DGE equals 1.136 GGE and 1 GGE equals .88 DGE. If you’re looking to compare the amount a tank can hold, a 24 GGE tank will hold about 21 DGEs.

Because GGEs and DGEs are common units of measurement at CNG stations, it’s important to have a basic understanding to ensure you are fueling your vehicle properly.

Ozinga has a variety of CNG fueling stations throughout the Midwest. Click the button below to find one in your area.