Interpret Diagnostics

[Mackab]

Experts,

For the past few weeks my 2000 Ford Windstar 3.8 liter seems to be guzzling gas. Currently in work on figuring current mpg but I know the guage is dropping alot faster than normal. It also seems a little more sluggish than the past. I have a scanner and have no codes. Can you take a look at the info the scanner provides matched against other Windstars you have worked on? Any help on analyzing this would be greatly appreciated.

Fuel System .... Closed Loop
Load Value .... 21.9%
Coolant Temp .... 197 F
Shrt Term Fuel Trim 1 .... -1.6% to .7%
Long Term Fuel Trim 1 .... 13.2%
Short Term Fuel Trim 2 .... -1.6% to 1.5%
Long Term Fuel Trim 2 .... 11.7%
Eng RPM .... 710
Ign Timing Advance .... 18.5
Intake Air Temp .... 60 F
Air Flow Rate .... .44 lb/min
Throttle Pos .... 18%
O2 Sensor 1 Bank 1 .... .695 v to .085 v
O2 Sensor 2 Bank 1 .... .825 v to .830 v
O2 Sensor 1 Bank 2 .... .720 v to .075 v
O2 Sensor 2 Bank 2 .... .825 v to .820 v
Baro Pressure .... 28.09 #hg
IAC Duty CYcle .... 30%
Throttle Pos .... .94 v
Engine Load .... 13%
Turbine Shaft .... 660
Output Shaft .... 0
Line Press Ctrl .... 15 psi
O2 Sensor 1 Bank 1 Heater .... On
O2 Sensor 1 Bank 2 Heater .... On
O2 Sensor 2 Bank 1 Heater .... On
O2 Sensor 2 Bank 2 Heater .... On
Rear O2 Trim Bank 1 .... 8.1%
Rear O2 Trim Bank 1 .... 0%
TCC Ratio .... .95

Also, the oil seems to get black within about 100 miles after an oil change. What could be causing this? Is it normal? Stationed overseas nad have no access to "professional" mechanics.