I know it's not hard to do, I do the math every other week with the trucks lousy 15.64 MPG. I'd typically fill it up at 175 and have about 4.2 gallons, which is about 41.666E MPG. I have different stories about removing lowering kit the previous owner had installed, too.
One shop said it wouldn't affect the reading and another said it would. I now believe the latter. The slight lean to the rear would offset when the light would be activated, giving a false reading. Which would account for the extra miles:
X [145 miles currently] + Y [amount of fuel used by offset angle affecting light] = 225 avg. miles per tank prior to removal.
This is why I was wondering about the mile per tank as opposed to the milage itself. I was running it on vapors to get the supposed 225 miles per tank. That, plus the change of tires (Metzler 880's to H-D stock) would have an extremely minor change too. The specs claim an average of 45 MPG, I should expect the gauge to get an "accurate" reading now. There was an even bigger picture that I should have looked at, live and learn. It's odd that only one shop knew that removing the kit would affect the reading.
All that aside, now I have to figure out why the clutch is slipping, adjustment or parts? I should know this afternoon. I appreciate the feedback.