I measure from full to fuel light. Fuel light is just over 21 gallons. I hit 16.75 (once) all freeway, but most of the time am just short of 15. At 15 I get 40 miles to the F mark, and about 70 for each quarter tank, with the needle slowing around the 1/2 mark.

F 40
3/4 100
1/2 180
1/4 260
Lite 320

acarr, 230/21.3 = 10.8 (still sucks)

The engine starts to break in by 15,000, but starts to get dirty by 30,000 and you need to do some cleanup. fuel filter, MAF, injectors, and ring groves if you take short trips and/or idle.