Can You Actually Escape A Sinking Car Underwater? | MythBusters

Scientific concepts / discoveries / nature & physics phenomena

Water pressure, pressure differential, and door/window release

• Hydrostatic pressure increases with water depth, so outside water pressure can exceed inside cabin air pressure.
• This creates a pressure differential that can hold car doors shut.
• The myth’s key condition is explained: doors can’t be forced open until pressures equalize (i.e., when the cabin fills with water and the inside/outside pressures match).

Small-scale pressure testing (tank/drum/door simulation)

• A 3-ft deep cylindrical water tank is used to model the pressure difference between:
  • an “open water” side, and
  • a “car cabin” side (a box that leaks water slowly around edges/corners).
• A Perspex piece represents the door.
• Depth-to-pressure equivalence is used:
  • each 1 ft lowered ≈ 0.5 PSI in the setup,
  • corresponding (as framed in the experiment) to very large forces on a real door (described as comparable to 1–2,000 lbs of force).

Real-world simulation of a sinking car (pressure + leakage + timing)

• A car is suspended from a crane, then lowered into a pool ~13 ft deep.
• Underwater cameras observe what happens as water floods crevices/openings.
• The team finds:
  • The door becomes workable only after the cabin reaches a condition where pressure equalizes.
  • Adam runs out of air before he can successfully open the door in the first trial (even though he eventually could open it in principle after equalization).

Survival/escape techniques tested

1. Door escape at the “right moment” before full submersion

   • Attempt to open the door while water has reached certain levels (ankles → waist → window-height).
   • Result: there is a very narrow time window; by the time water is about halfway up the window, differential pressure is too strong to force the door.

2. Window escape feasibility (manual vs electric windows)

   • Differential pressure is shown to be extremely difficult to overcome:
     • Both manual and electric windows fail to open under similar conditions.
   • Electric window electronics appear to remain functional for some time underwater:
     • they did not short out immediately,
     • battery durability was tested for 45 minutes,
     • but pressure still prevents opening.

3. Breaking a window using appropriate tools

   • Ordinary attempts (keys, phone, steel-toed boots) do not crack the glass.
   • Commercial “emergency escape” tools work quickly:
     • targeted tools crack via a center-punch/penetration mechanism.
   • Explanation:
     • Car windows are tempered glass.
     • Once fractured, stored stresses cause the glass to shatter/tension-fail, producing an exit hole.

4. “High-voltage” / activated window release approach

   • A window is rigged with lubrication and a high-voltage trigger intended to overcome the pressure differential.
   • Trial result: water rapidly floods the cabin; Adam escapes via the window shortly after.

5. “Patience” / energy conservation escape strategy

   • Technique: wait for the car to settle/fill and pressures equalize, then calmly open the door near the end.
   • Claimed benefits:
     • reduced frantic effort → less oxygen use,
     • once equalized, opening becomes feasible.
   • In the test, Adam survives and times underwater exposure (reported as about 1 minute 37 seconds).

Researchers / sources featured (end of video credits or stated people/organizations)

• MythBusters (show; no specific host names listed in the subtitles besides participants)
• Adam (host/host-participant; full name not given in subtitles)
• Jamie (host/host-participant; full name not given in subtitles)
• Shawn (safety diver; referenced as safety diver “Shawn”)
• AAA (American Automobile Association), cited for statistics:
  • estimated 11,000 vehicles go off road into water (year mentioned: “last year”)
  • cited 300 deaths (as stated in subtitles)
• Campolindo High School (Moraga) (aquatic center used for pool tests)