Overview
This MythBusters "Car Crazy" episode investigates two automotive myths: whether square wheels can provide a smooth ride at high speeds, and if two cars conjoined bumper-to-bumper can drive together as depicted in the movie "Date Night." Both myths involve extensive engineering, testing, and data collection.
Square Wheels Myth: Design & Construction
- Adam and Jamie design ultra-strong, steel square wheels to handle a truck's weight.
- Tires are fitted to the square rims, eventually using larger tires for easier mounting.
- All four square wheels are assembled and reinforced to minimize risk of failure.
Square Wheels Myth: Testing & Results
- Objective data collected from sensors on suspension, steering, and passenger seats.
- Control run with round wheels at up to 60 mph confirms smooth ride baseline.
- First square wheel test: truck experiences rough ride, partial smoothing as speed increases, but catastrophic wheel hub failure halts test.
- Data shows vibrations decrease at higher speed, supporting the myth's concept.
- Small-scale testing reveals that offsetting two wheels by 45° yields smoother ride than other orientations.
- Second full-scale test with 45° wheel offset achieves a smoother ride up to 18 mph before tires/brakes fail.
- Data confirms smoother (though still harsh) ride at higher speed, but significant mechanical destruction occurs.
Date Night Conjoined Cars Myth: Build & Setup
- Carrie, Tori, and Grant construct a steel frame to rigidly connect two cars, one rear-wheel drive (taxi), one all-wheel drive (sports sedan).
- Safety considerations prevent using actual crash-connection.
Date Night Conjoined Cars Myth: Maneuver Testing
- Straight-line forward and reverse driving is successful at 40 mph, though control and braking are severely compromised.
- Attempted 90° turns fail repeatedly, regardless of wet road or bald tires; only achieve accidental turn in unintended direction due to loss of traction.
- 180° spin maneuver is practiced and then executed successfully with front drivers turning opposite directions and wet road conditions, resulting in a dramatic spin similar to the movie.
Square Wheels Myth: Hill Climb Test
- Theory: square wheels could perform better on loose dirt by increasing surface area and "levering" up the hill.
- Both round and square wheels achieve the same distance up a steep, dirt-covered slope; no advantage found for square wheels.
Decisions
- Square wheels for smooth ride called plausible: Smoother ride is possible at higher speed, but practical issues remain.
- Square wheels for hill climbing called busted: No advantage over round wheels.
- Date Night 180° spin maneuver confirmed: The spin is achievable under controlled conditions.
Action Items
- TBD – Team: Consider future tests or contexts where non-circular wheels might offer advantages.