Wyoming Engine & Jake Brake Rules

No statewide ban in Wyoming. State law only demands a working muffler and no cutout or bypass (Wyo. Stat. 31-5-953). Real restrictions are local: 'no engine brake' signs show up around the Jackson resort area, through Star Valley towns like Afton on US-89, and on descents into small towns. A muffler beats a state noise charge, not a posted local ordinance. Keep using the engine brake on Wyoming's long grades where no sign is posted.

Ban scopeLocal / posted

Muffler lawYes (the legal hook)

Where postedSigns show up around the Jackson resort area, through Star Valley towns like Afton and Thayne on US-89, near Cody, and on descents into small towns

FineLocal noise-ordinance citation set by the town or county, commonly about $50-$500

A detail here is flagged medium confidence — confirm with the state DMV or the local ordinance before you rely on it.

01 The rule

How Wyoming handles engine braking

02 On the road

What to watch for

Ban scope: Local / posted
Where posted & enforced: Signs show up around the Jackson resort area, through Star Valley towns like Afton and Thayne on US-89, near Cody, and on descents into small towns. Resort and residential zones enforce; the open interstate grades rarely do.
Muffler / noise law: Yes, the real legal hook
Fine: Local noise-ordinance citation set by the town or county, commonly about $50-$500.

Wyoming Engine Brake FAQ

Are engine brakes banned in Wyoming?

Wyoming has no statewide ban. The restriction is local and posted on "NO ENGINE BRAKE" signs. No statewide ban in Wyoming.

Where are the "NO ENGINE BRAKE" signs in Wyoming?

Signs show up around the Jackson resort area, through Star Valley towns like Afton and Thayne on US-89, near Cody, and on descents into small towns. Resort and residential zones enforce; the open interstate grades rarely do.

What is the fine for using an engine brake where it is banned in Wyoming?

Local noise-ordinance citation set by the town or county, commonly about $50-$500.

Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://codes.findlaw.com/wy/title-31-motor-vehicles/wy-st-sect-31-5-953/. See our Terms & Disclaimer.

03 Related

Check Wyoming before you roll

Live weather, closures, and hazards on one map. Free, no account.

Open Live Map →

Wyoming Engine & Jake Brake Rules

How Wyoming handles engine braking

What to watch for

Wyoming Engine Brake FAQ

More for Wyoming

Wyoming Speed Limits

Wyoming 511

All States

Check Wyoming before you roll