# Arkansas SB478: TO CREATE THE ARKANSAS DIESEL ENGINE FREEDOM ACT OF 2025; AND TO PROHIBIT STATE ENFORCEMENT OF FEDERAL REGULATION OF CERTAIN TYPES OF DIESEL ENGINES. Arkansas SB478, TO CREATE THE ARKANSAS DIESEL ENGINE FREEDOM ACT OF 2025; AND TO PROHIBIT STATE ENFORCEMENT OF FEDERAL REGULATION OF CERTAIN TYPES OF DIESEL ENGINES., is a 2025 Regular Session Senate bill sponsored by Gary Stubblefield (Republican); status enacted, last action 2025-04-18 (Notification that SB478 is now Act 738) (as of 2026-10-19). - Canonical: https://policyrisk.com/state-bill/AR-SB478-2025 - As of: 2026-10-19 - Plain-text twin of the page above; the HTML and this file carry the same facts. ## Facts - Bill: Arkansas SB478 - State: Arkansas - Session: 2025 Regular Session - Title: TO CREATE THE ARKANSAS DIESEL ENGINE FREEDOM ACT OF 2025; AND TO PROHIBIT STATE ENFORCEMENT OF FEDERAL REGULATION OF CERTAIN TYPES OF DIESEL ENGINES. - Status: enacted - Chamber: Senate - Introduced: 2025-03-17 - Last action: 2025-04-18, Notification that SB478 is now Act 738 - Sponsor: Gary Stubblefield (Republican) - Cosponsors: 0 - Touches household money: no - Roll calls: 2 (121 yes, 3 no in all) - Economic provisions PRIA read: 4 ## Summary No summary available. ## Bill overview: provisions PRIA read - Arkansas protects qualifying diesel engine use: benefit, low. Qualifying diesel engines run only in Arkansas and do not require diesel exhaust fluid. Arkansas law protects the right to make, sell, install, use, and operate these engines within the state. State and local agencies, officials, and workers cannot restrict their production, sale, or use. They also… - Public workers face firing and five-year bans: cost, high. A state or local official, agent, worker, or representative who violates this law must be terminated from that government entity. The person also cannot hold public office or obtain state employment for five years. - Government violators face fines and enforcement suspensions: cost, low. State entities that break this law face civil penalties of up to $5,000 for each violation. State entities include state agencies, local governments, and their officials, agents, workers, and representatives. A violating agency or local government immediately loses authority to enforce state vehicl… - Engine sellers face labels and export limits: cost, low. An exempt diesel engine made and sold exclusively in Arkansas must clearly carry a label for Arkansas-only use. These engines operate only in Arkansas and do not require diesel exhaust fluid. Export for use in another state is barred unless the engine complies with applicable federal laws. ## Sponsors and cosponsors - Sponsor: Gary Stubblefield (Republican), Senate ## Roll call votes | Date | Chamber | Motion | Result | Yes | No | Other | | --- | --- | --- | --- | --- | --- | --- | | 2025-04-14 | House | House Vote - Monday, April 14, 2025 5:15:19 PM | pass | 86 | 3 | 6 | | 2025-04-08 | Senate | Senate Vote - Tuesday, April 8, 2025 6:41:21 PM | pass | 35 | 0 | | ## Actions (15) - 2025-04-18: Notification that SB478 is now Act 738 (Senate) - 2025-04-15: DELIVERED TO GOVERNOR. (Senate) - 2025-04-15: Reported correctly enrolled and ordered delivered to the Governor. (Senate) - 2025-04-14: ORDERED ENROLLED (Senate) - 2025-04-14: Returned from the House as passed. (Senate) - 2025-04-14: Returned to the Senate as passed. (House) - 2025-04-14: Read the third time and passed and ordered transmitted to the Senate. (House) - 2025-04-09: Returned by the Committee Do Pass (House) - 2025-04-08: Read the first time, rules suspended, read the second time and referred to the Committee on PUBLIC TRANSPORTATION- HOUSE (House) - 2025-04-08: RECEIVED FROM THE SENATE (House) - 2025-04-08: Ordered immediately transmitted to the House. (Senate) - 2025-04-08: Read the third time and passed. (Senate) - 2025-04-07: Returned by the Committee, with the recommendation that it Do Pass (Senate) - 2025-03-17: Read first time, rules suspended, read second time, referred to TRANSPORTATION, TECHNOLOGY & LEGISLATIVE AFFAIRS - SENATE (Senate) - 2025-03-17: Filed (Senate) ## Bill text - SB478 - Introduced, 2025-03-17: [PDF](https://www.arkleg.state.ar.us/Home/FTPDocument?path=%2FBills%2F2025R%2FPublic%2FSB478.pdf) - Act Version: [PDF](https://www.arkleg.state.ar.us/Acts/FTPDocument?path=%2FACTS%2F2025R%2FPublic%2F&file=738.pdf&ddBienniumSession=2025%2F2025R) ## Related bills - HB1265: AN ACT FOR THE UNIVERSITY OF ARKANSAS AT LITTLE ROCK APPROPRIATION FOR THE 2025-2026 FISCAL YEAR. (enacted) - HB1237: TO PROHIBIT MEDICAL PROFESSIONALS FROM SOLICITING INJURED INDIVIDUALS; AND TO SET PENALTIES FOR A VIOLATION OF THE PROHIBITION OF SOLICITATION OF INJURED INDIV… (failed) - HB1686: TO AMEND THE LAW CONCERNING LICENSES TO CARRY CONCEALED HANDGUNS. (failed) - SB440: TO AMEND THE LAW CONCERNING EMBALMERS AND FUNERAL DIRECTORS; TO REGULATE THE USE OF ALKALINE HYDROLYSIS; AND TO REGULATE ALKALINE HYDROLYSIS FACILITIES. (failed) - HB1695: TO CLARIFY THE FORECLOSURE PROCESS FOR PROPERTY SUBJECT TO A MUNICIPAL LIEN; TO ALLOW A MUNICIPALITY TO PETITION TO SET ASIDE THE SALE OF PROPERTY TO CERTAIN P… (failed) - HR1012: TO AMEND THE RULES OF THE HOUSE OF REPRESENTATIVES OF THE NINETY-FIFTH GENERAL ASSEMBLY; TO REQUIRE THAT A MEMBER OF THE HOUSE OF REPRESENTATIVES BE SELECTED A… (failed) ## Sources - [SB478 - Introduced (PDF)](https://www.arkleg.state.ar.us/Home/FTPDocument?path=%2FBills%2F2025R%2FPublic%2FSB478.pdf) - [Act Version (PDF)](https://www.arkleg.state.ar.us/Acts/FTPDocument?path=%2FACTS%2F2025R%2FPublic%2F&file=738.pdf&ddBienniumSession=2025%2F2025R) ## Related - [HB1265: AN ACT FOR THE UNIVERSITY OF ARKANSAS AT LITTLE ROCK APPROPRIATION FOR THE 2025…](https://policyrisk.com/state-bill/AR-HB1265-2025) - [HB1237: TO PROHIBIT MEDICAL PROFESSIONALS FROM SOLICITING INJURED INDIVIDUALS; AND TO S…](https://policyrisk.com/state-bill/AR-HB1237-2025) - [HB1686: TO AMEND THE LAW CONCERNING LICENSES TO CARRY CONCEALED HANDGUNS.](https://policyrisk.com/state-bill/AR-HB1686-2025) - [SB440: TO AMEND THE LAW CONCERNING EMBALMERS AND FUNERAL DIRECTORS; TO REGULATE THE US…](https://policyrisk.com/state-bill/AR-SB440-2025) - [HB1695: TO CLARIFY THE FORECLOSURE PROCESS FOR PROPERTY SUBJECT TO A MUNICIPAL LIEN; TO…](https://policyrisk.com/state-bill/AR-HB1695-2025) - [HR1012: TO AMEND THE RULES OF THE HOUSE OF REPRESENTATIVES OF THE NINETY-FIFTH GENERAL…](https://policyrisk.com/state-bill/AR-HR1012-2025) - [Arkansas bills](https://policyrisk.com/states/arkansas/bills) - [Arkansas state hub](https://policyrisk.com/states/arkansas) - [All state legislation](https://policyrisk.com/state-bills) Source: PRIA, https://policyrisk.com/state-bill/AR-SB478-2025 (as of 2026-10-19).