I get a combined of about 28. I drive a 90 mile commute round trip every day. I get a full week (5 round trips) before needing to fill up. I put roughly 16 Gallons in every fill-up.
90x5 = 450 miles
450miles/16gal = 28.12 MPG
Currently I have a stock tune (set up for the 3.27's). I'm going to get a tune on the car to REALLY make use of the 2.73's that are in the rear dif, and then see if I can get into the 30's.
1997 LX Sport 4.6L 2.73 , MODS=SCT tuned/J-Mod/Trans Cooler/Dyno max Cat-Back/NgkPlugs/Mac cold air/March UD's/FRPP aluminumcarrier3.73's(spare for strip use)/ PI cams + PI intake manifold w/adapter plate/ Mark VIII Convertor/80mm L-Maf/70mm TB/ Mark VIII 1 piece shaft/Cobra R' wheels/ Kumhos 235/60/16 - White leather w/ blue cloth seats - white face gauges in 95 cluster