Oracle database file

Need space in hard disk after this database clean up the used space in the ORANT\DATABASE\USR1ORCL.ORA does not go down, I have the file size set to 1.8 GB and the storage manager shows 1.7 used. Is this a high water mark or is really the space used in the file.
Before Cleanup
Export DMP File 558 Meg
Export Time > 2 Hours
Import Time > 3 Hours
Traffic Table 6,158,000 Rows
Traffic Report > 12 Minutes

After Cleanup
Export DMP File 199 Meg
Export Time < .5 Hours Import Time > 1 Hour
Traffic Table 757,000 Rows
Traffic Report < 30 Seconds