Does Adding Weight to a Hot Wheels Car Make It Go Faster?

Ben Massfeller | Grade 5 | 2026 Science Fair

About This Project

I built a speed trap called the M.A.S.S. Trap (Motion Analysis & Speed System) with my dad. It uses infrared sensors and an ESP32 computer to time Hot Wheels cars on a 5.85-meter track.

I tested whether adding weight to a car makes it faster or slower by running two Ford F-150 trucks with 0g, 3.5g, 7g, and 14g of tungsten weights.

What I Found

• A little extra weight (3.5g) made both cars faster
• Too much weight (14g) made the heavier car slower
• The lighter car kept getting faster at every weight
• There's a "sweet spot" for the best speed

Repository Structure

submission/     # Written report (hypothesis, variables, results, conclusion)
data/           # Raw CSV data from all race runs
photos/         # Experiment photos and setup
presentation/   # Display board materials
docs/           # Judge-facing data page (GitHub Pages)

Live Data

View the raw data and interactive results at: https://ryan4n6.github.io/ben-science-fair/

The M.A.S.S. Trap

The speed trap system that collected this data is an open-source project:

• GitHub: github.com/Ryan4n6/MASS-Trap
• Project Site: ryan4n6.github.io/MASS-Trap