2x4 vs 4x4 mileage
 

hope someone can help, thinking about buying 08 f150 4x4 supercrew,
Ihave 04 f150 supercab 2x4 it gets 18-20 mpg, can i expect the same out of 08 if 4 wheel drive not engaged or does it being a 4x4 lower mpg anyway
thanks