Plastic pollution and energy shortages are pressing issues in today’s world. Waste plastic pyrolysis attempts to solve these problems by eliminating waste from the environment while creating a viable alternative fuel to replace conventional fuels. This research examined whether waste plastic pyrolysis fuels are similar to conventional diesel and, thus, a plausible alternative fuel. We created three distinct waste plastic pyrolysis fuels: high-density polyethylene, polypropylene/low-density polyethylene, and a mixed fuel. Four tests isolated specific characteristics of each fuel: efficiency, calorific value, burn time, and relative density. Results showed that waste plastic pyrolysis fuels were not comparable in performance to conventional diesel: diesel had the longest burn time, the highest calorific value, and the highest efficiency of all fuels tested. These results suggest that conventional diesel is a superior fuel compared to waste plastic pyrolysis fuels.