The document describes experiments conducted to design the optimal LEGO car to travel the farthest distance. Researchers tested 4 factors (axle base, car weight, wheel base, wheel size) across 8 control variables to assemble different car designs. The cars were tested by timing how far they rolled down a ramp, and the data was analyzed to determine the highest performing design. Financial considerations were also examined to find the most cost-effective car. Analysis showed that a narrow axle base, long wheel base, car with added weight, and two small wheels in front and two large in back performed best while keeping costs reasonable.

2. In order to design the LEGO cars that run the
farthest, we use DOE to design experiments,
assemble the cars, ramp testing and data
analysis to get the best performing car. We
tested 4 different factors and 8 control variables
to come up with the best combination of
performance cars. Finance was also a
consideration in our experiments, and we
worked to create the most reasonably priced
LEGO car that could go the farthest.
EXECUTIVE
SUMMARY

4. Axle Base
Car Weight
Wheel Base
Wheel Size

5. Variables and
measurement
Axle Base
Car Weight
wide/narrow axle base
No weight block on car/weight block
on car
Wheel Base
Wheel Size
Long/short wheel base
Large wheel on front & small wheel
on back/Small wheel on front &
large wheel on back

6. EXPERIMENT DESCRIPTION
ASSEMBLE
RAMP
TEST
DATA
COLLECT
ANALYSIS
Design and assemble
different LEGO cars based
on 4 factors and variables.
Ran different assembled LEGO
cars from the same ramp
Collected distance data Analysis data based on factors,
distances and variables to
determine the best LEGO car.

7. DOE(design of Experiment) and
Factorial Design
We try to eliminate the noise factors in the
following：
Make sure all the factors and variables are truly
contributed to distance
The ramp and road are same for all tested LEGO car
Done the experiment in the same day and
environment
Randomize the trials to negate the effect of lurking
variables

8. ANALYSIS
We find out that for each factor, narrow axle base,
long wheel base, have weight on the car, two small
wheel on front/two large on back have better
performance on distance.

9. ANALYSIS

10. The best performance LEGO car is only slightly
expensive than other car we made(12700 vs.
11900)
Narrow Axle Base was more cost efficiency
and better than wider one
Long wheel base cost more but ran further
than short one
Weight majorly increase the price but make
car ran further
Two small wheels on the front and two large
on the back cost less than four same wheels
but have similar performance.
FINANCIAL ANALYSIS
Axle Base
32.1%
Wheel Size
23.4%
Car Weight
22.6%
Wheel Base
21.9%

11. Based on analysis and experiment, our best recommendation of combination is narrow axle
base, long wheel base, more car weight, and two small wheels in front/two large on back.
For cost efficiency, we recommend:
Instead of four same wheels, two small wheels on front and two large wheels on back can
perform similar distance but have cost efficiency.
Instead of and , use same amount of will be cheaper but have
same performance.
RECOMMENDATION