Gas mileage of a 99 3.4 V6 4X4

Hey guys (and gals), I found this truck and it's a 99 tacoma, 4x4, 3.6. Does anybody know what the ACTUAL gas mileage of it would be??? Fueleconomy.gov says it's about 18/22 but i know that isn't correct. What about with the 4wd disengaged. Would it be different than with the 4wd engaged?

You shouldn't engage the 4WD driving on dry pavement, so all the mileage figures are for 2WD. 4WD is for off-road and slippery conditions only.

The actual mileage is 16-22 mpg. If you are heavy-footed, it will be worse.