Fuel for Thought


By Greg Huggins
Posted Jan 19th 2023 5:37AM

There has been some debate among truck drivers over the years about the legality of carrying and using portable gas generators (and gas cans) on their CMV (Commercial Motor Vehicle) for use as a source of power to run various appliances in their cab such as heaters, air conditioners, cooking equipment and refrigerators. Some say you cannot carry any auxiliary equipment that runs on fuel that is gravity fed (equipment without a fuel pump). Some say you cannot carry more than five gallons of gas in a can or tank on a CMV.

§ 393.65(d) addresses this issue. It appears that since 1971 this regulation has existed and it does prohibit the use of gravity fed or siphon fed for the CMV and auxiliary equipment. 

As for the five gallon rule, there does not seem to be one that specifically regulates the amount fuel you can carry in a portable can or tank, however, back in 1970-1971 when the regulation was addressed (this regulation has been on the books since the 1950s), it was only addressing fuel systems and not necessarily tank capacity.

Recently, as in September 2020, the issue of gravity fed tanks on CMVs was again on the table for the FMCSA (Federal Motor Carrier Safety Administration) to consider an exemption to part § 393.65(d) after Charles Machine Works filed the application for exemption in 2019.

The following excerpt is from Docket (FMCSA-2019-0069) on Regulations.gov : 

FMCSA Decision

FMCSA has evaluated the CMW (Charles Machine Works) exemption application, and the comments received. Based on the discussion above, FMCSA believes that allowing the use of gravity or syphon-fed fuel systems for auxiliary equipment installed on or used in connection with CMVs that operate only when the CMV is not operating on the highway is likely to provide a level of safety that is equivalent to, or greater than, the level of safety achieved without the exemption.

Terms and Conditions for the Exemption

The Agency hereby grants the exemption for a 5-year period, beginning September 16, 2020 and ending September 16, 2025. During the temporary exemption period, motor carriers will be allowed to use gravity or syphon fed fuel systems for auxiliary equipment installed on or used in connection with CMVs that operate only when the CMV is not operating on the highway.

The exemption will be valid for 5 years unless rescinded earlier by FMCSA. The exemption will be rescinded if: (1) Motor carriers operating CMVs fail to comply with the terms and conditions of the exemption; (2) the exemption has resulted in a lower level of safety than was maintained before it was granted; or (3) continuation of the exemption would not be consistent with the goals and objectives of 49 U.S.C. 31136(e) and 31315(b).

For those of you that have gravity fed equipment on your CMV, like a portable generator, you are exempt from 393.65(d) until September 16, 2025. Not that this regulation is enforced often, but in the event you are cited for violation of 393.65(d) due to having this type of equipment on your truck, it might be a good idea to keep a copy of this exemption in your permit book for future reference. 

The exemption can be found (and printed from) the following link: Exemption from 393.65(d).

See you down the road,