12.2 MPG?!?!

1, miles traveled per tank= 132.41
2, gallons used= 10.8
3, engine size= 3.0 12V
4, tire size= 31"
5, year and model= 1997 Montero GL Dakar SWB
6, other mods that may affect fuel economy= I'm pretty sure it has a smaller muffler than it should. When I'm not giving it gas I hear little explotions <img src="/forums/images/graemlins/scared.gif" alt="" />

Pleas see this post where I have more details about my poor mpg <img src="/forums/images/graemlins/scared.gif" alt="" />