Staff Answer
Sep 21, 2026 - 06:31 AM
Yes, in most cases you do.
While a 2009 Smart Fortwo is very light for a vehicle—weighing around 1,800 to 1,850 lbs curb weight—whether you legally or practically need a supplemental braking system depends on legal standards, safety, and wear on your motorhome.
1. Legal Requirements
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State & Provincial Laws: Most U.S. states and Canadian provinces require a supplemental braking system on any towed vehicle or trailer exceeding a specific weight limit.
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1,500 lb. Threshold: States like California, Idaho, and Nevada mandate brakes for anything towed over 1,500 lbs. Since the 2009 Smart Fortwo weighs ~1,800 lbs, it automatically exceeds the threshold in those states.
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3,000 lb. Threshold: Many other states use a 3,000 lb threshold. However, if you plan to travel across state lines, you must comply with the strictest jurisdiction you drive through.
2. Safety & Vehicle Wear
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Breakaway Protection: If the Smart car accidentally disconnects from your motorhome while towing, a supplemental braking system equipped with a breakaway switch will automatically engage the car’s brakes to bring it to a safe stop.
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Reduced Stopping Distance: Even small, light cars add momentum to a stopping RV. A braking system reduces strain on the motorhome’s brakes and shortens total stopping distances during emergency stops.
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Liability & Insurance: Driving without a required supplemental brake system can void insurance coverage or increase legal liability in the event of an accident.
Recommended Next Steps
If you are flat-towing (dinghy towing) or dolly-towing your 2009 Smart Fortwo, consider portable options like the Blue Ox Patriot or Demco Stay-in-Play / Air Force One systems, which easily accommodate lighter dinghy vehicle
