# 2026-03257: Tiny Fuel Tanks OK, But Only When Trailers Aren't Moving

2026-03257, Parts and Accessories Necessary for Safe Operation; Auxiliary Fuel Tanks, is a Federal Register rule from Transportation Department, Federal Motor Carrier Safety Administration published 2026-02-19, effective 2026-03-23 (as of 2026-06-11).

- Canonical: https://policyrisk.com/federal-register/2026-03257
- As of: 2026-06-11
- Plain-text twin of the page above; the HTML and this file carry the same facts.

## Facts
- Document number: 2026-03257
- Title: Parts and Accessories Necessary for Safe Operation; Auxiliary Fuel Tanks
- Type: Rule
- Agencies: Transportation Department; Federal Motor Carrier Safety Administration
- Citation: 91 FR 7890
- Published: 2026-02-19
- Effective: 2026-03-23
- Comments close: not stated
- Significant: no
- Touches household money: no
- Regulation identifier numbers: 2126-AC94
- Last updated: 2026-06-11

## In one line

Tiny Fuel Tanks OK, But Only When Trailers Aren't Moving

## Summary

The FMCSA is updating fuel tank rules to allow small auxiliary fuel tanks (up to 5 gallons) on trailers to use gravity or siphon feeds, but only when the vehicle isn’t moving. This change helps truck trailer makers by easing a rule without hurting safety. The new rule kicks in on March 23, 2026, and anyone wanting to challenge it must act by that date.

## Abstract

FMCSA amends its fuel tank requirements to add an exception to the prohibition on gravity and syphon feeds for auxiliary pumps with a nominal fuel tank capacity of not more than five gallons mounted on the trailer chassis frame or trailer bed, for purposes other than operation of the motor vehicle, that are operated only when the motor vehicle is not in motion. This revision responds to a petition for rulemaking from the Truck Trailer Manufacturers Association (TTMA). The revision provides relief from a regulatory requirement without impacting safety.

## Effects PRIA read

- Allows small trailer fuel tanks to use gravity feed: benefit, low. If you make or own truck trailers or auxiliary fuel pumps, the rule lets auxiliary pumps with a nominal fuel tank capacity of not more than five gallons mounted on the trailer chassis frame or trailer bed supply fuel by gravity or siphon only when the motor vehicle is not in motion. This change tak…
- FMCSA says small-entity costs are de minimis: benefit, low. FMCSA certified this rule will not have a significant economic impact on a substantial number of small entities and said any cost savings for owners of eligible auxiliary pumps are expected to be de minimis. The agency did not quantify the savings.

## Related documents

- [2026-08144](https://policyrisk.com/federal-register/2026-08144): Administrative Rulemaking, Guidance, and Enforcement Procedures, 2026-04-27
- [2026-20734](https://policyrisk.com/federal-register/2026-20734): Parts and Accessories Necessary for Safe Operation; Application for Exemption From Aurora Operations, Inc (USDOT #341156), 2026-10-09
- [2026-20649](https://policyrisk.com/federal-register/2026-20649): Qualification of Drivers; Commercial Vehicle Safety Alliance; Application for Exemption, 2026-10-08
- [2026-20524](https://policyrisk.com/federal-register/2026-20524): Agency Information Collection Activities; New Information Collection: Hours of Service of Drivers; Pilot Program To Allow Commercial Driver…, 2026-10-07
- [2026-20476](https://policyrisk.com/federal-register/2026-20476): Agency Information Collection Activities; New Information Collection: Hours of Service of Drivers: Pilot Program To Allow Commercial Driver…, 2026-10-06
- [2026-20325](https://policyrisk.com/federal-register/2026-20325): Clarification to the Applicability of Emergency Exemptions; Response to Petitions for Reconsideration, 2026-10-05

## Sources
- [2026-03257 on federalregister.gov](https://www.federalregister.gov/documents/2026/02/19/2026-03257/parts-and-accessories-necessary-for-safe-operation-auxiliary-fuel-tanks)
- [2026-03257 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2026-02-19/pdf/2026-03257.pdf)

## Related
- [Previous: 2026-03256, Parts and Accessories Necessary for Safe Operation; Brakes on Portable Conveyors](https://policyrisk.com/federal-register/2026-03256)
- [Next: 2026-03258, Qualifications of Drivers; Vision Standards Grandfathering Provision](https://policyrisk.com/federal-register/2026-03258)
- [All Federal Register documents](https://policyrisk.com/federal-register)

Source: PRIA, https://policyrisk.com/federal-register/2026-03257 (as of 2026-06-11).