In "Star Trek Nemesis" Picard ordered the Enterprise to Romulus at Warp 8. This is the highest speed that was revealed. However, it is likely the ship could reach warp 9.9 if pushed.
- If the Enterprise-D could make Warp 9.65 in ST:TNG "Q Who", then the Enterprise-E certainly could, as well. --ProfessorTrek 10:41, February 13, 2012 (UTC)
Also, their have been rumours that the ship was refitted with a Quantum Slipstream drive. This would of allowed them to reach Warp 20 (depending on the time period).