This technology allows the construction spacecraft that rely on the Construction Drive for propulsion: Small Cargo and Large Cargo ships, Light Fighters, Recyclers, and Espionage Probes.
With each level of the Combustion Drive technology developed, the speed and fuel efficiency of these ships are increased by 10% of their base value. (After researching Impulse Drive Technology Level 5, the drive engines in Small Cargo ships are automatically upgraded from Combustion to Impulse, which doubles their base speed. From that point onward, Small Cargo Ships benefit from improvements in Impulse Drive technology).