There are no suspension lift limits or frame height limits in Idaho. Bumper height is limited to 30 inches for 4x4s under 10,000 lbs. GVWR. As long as drivers keep their bumper heights in check, the install of suspension lift kits, aftermarket wheels and tires, performance shocks, aftermarket bumpers, and grille guards is legal.
Update: Effective 6/1/10, Canyon County and the city of Kuna within Ada County require emissions testing.
 Code |
Idaho details its street legal laws in the Idaho Statutes (IS). |
IS Title 49 | ||||||||||||||||||||||||||||
 Dimensions |
In Idaho, vehicles must be no larger than 102 inches wide, 14 feet tall, or 45 feet long for a single vehicle. |
IS 49-1010 | ||||||||||||||||||||||||||||
 Tires |
All tires on vehicles driven in Idaho must be safe. There is no listed minimum tire tread depth or restriction on re-grooved tires . |
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 Wheels |
Wheels are not covered in Idaho’s laws. |
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 Brakes |
Vehicles driven in Idaho are required to have brakes on all 4 wheels. The brakes must be capable of stopping the vehicle from a speed of 20 mph within 30 feet. A secondary, mechanical, parking brake is also required. |
IS 49-933 | ||||||||||||||||||||||||||||
 Steering |
Idaho does not have any steering related laws. |
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 Suspension |
There are no specific suspension laws in Idaho. |
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 Frame |
To comply with Idaho’s street legal laws, a vehicle’s frame cannot be lower than the lowest point of the vehicle’s wheels. |
IS 49-965 | ||||||||||||||||||||||||||||
 Bumpers |
Idaho requires that bumpers be at least 4.5 inches tall. Bumper heights are limited according to the vehicle’s GVWR.
( Measured to the bottom of the bumper. ) |
IS 49-966 | ||||||||||||||||||||||||||||
 Fenders |
Fenders and mud flaps are both required in Idaho. |
IS 49-949 | ||||||||||||||||||||||||||||
 Lights |
In addition to headlights and tail lights, vehicles in Idaho are allowed to have additional lights installed. When a vehicle is equipped with extra lighting, no more than 4 front lights can be on at one time while driving.
( Measured to the center of the light. ) |
IS 49-905 IS 49-906 IS 49-918 IS 49-927 |
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 Windows |
It is unclear if windshields are required in Idaho. Vehicles with windshields are required to have windshield wipers. |
IS 49-943 | ||||||||||||||||||||||||||||
 Exhaust |
In Idaho, vehicles are required to be equipped with mufflers. Exhaust cutouts and bypasses are not allowed to be installed. |
IS 49-937 | ||||||||||||||||||||||||||||
 Engine |
Engine modifications and engine swaps are not covered in Idaho’s laws. |
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 Emissions |
Canyon County, Ada County, and the city of Kuna require emissions testing in Idaho. |