It is quite possible that the engines are sublight as it takes light only a few hours to travel from the sun to the outer limits of our solar system.
Actually, it takes at least 6 game days (as there are 30 in one turn) to do that (and that is if you mod engines to get 30 MPs ). Light does not take 6 days to reach the edge of a system, so all engines must be sub-light. That, and they are all specifically labeled as sub-light.
[ April 10, 2003, 19:26: Message edited by: Imperator Fyron ]