Does the 2004 engine perform slightly better than the 2003?

[Doug]

Just to join the opinions I have a 2003, very early production. My average according to the meter is 10.8. This is 50/50 (Highway) and I consider myself to have a LIGHT foot. My calculations are always about 2 mpg higher.
Straight highway I calculated 15.5 at best. I just wonder how accurate theses GM meters are, should we trust them, I would suggest to calculate your own milage.
On another note I am looking into programmers and exhaust systems. Pretty confused on which to go with. Any suggestions? Thanks in advance!

Doug
2003 Metalic Red H2
Adventure Series. w/navigation/Sat Radio/Winch