After regulators failed to agree to a nationally recognized, gallon-equivalent measure for sales of liquefied natural gas, fleets that rely on LNG-fueled vehicles will continue to face a state-by-state patchwork of standards for at least one more year.

Meeting in Detroit earlier this month, the National Conference on Weights and Measures failed to agree to a proposal that would set the amount of LNG that provides the same amount of power as one gallon of diesel fuel.

The Diesel Gallon Equivalent (DGE) standard needed approval from two panels of the conference, which is made up of state regulators, to take effect. While one of the panels agreed with the proposal, the other did not, sending it back to the regional level for more work, reports the Houston Chronicle.

CNG has been priced for two decades in a method that converts 5.66 pounds of gas to 1 gallon of gasoline, allowing an easy cost comparison as well as using terms that drivers are used to seeing. The Gasoline Gallon Equivalent (GGE) figure allowed for easy comparison, although some delegates at the meeting in Detroit expressed an interest in adjusting that figure as well.

Without the national standard, retailers are allowed to use a DGE or GGE price when selling LNG — as they do now — but consumers will find they get a slightly different amount of fuel state-by-state, said Kathryn Clay, vice president for policy strategy at the American Gas Association.