(#9 above)Like I said Math not one of my strong points, but you see my point? (#10 above) The full impulse I got from the trek Encyclopedia (p.135, Impulse Drive) which puts it at .5C. As I said this is confusing, if this could be decided once and for all it would be usefull. B'cus of the lack of Tech stuff for Battlestar Galatica I had to come up with my own. The BSG stuff uses a 'Gravimetric Drive System' it accelerates toword light speed and as it does so the 'Gravimetric Drive' lowers the mass of the vessel to zero thereby sidesteping Ol' Albert.
Thing is though, you never see any trek battles where they are going at full impulse. They probably use thrusters or whatever which would probably similar to the speeds on BC. If you wanted to put impulse speeds on, there should be another engine system i recon.