4 Wheel Drive/SUVs: Chev and Ford comparison, best gas milage, speed overdrive transmission

Question
In trying to decide wheather to purchase a new Ford Explorer, or a Chevrolet Trailblazer I noticed that the Ford has a 5 speed  (overdrive) transmission as compared to the Chev's 4 speed.  The Chev, however, has a 2 wheel high setting on the 4x4 switch and the Ford does not.
Chev has 4 settings.  (1)2 wheel high  (2) Auto 4 wheel (3) 4 wheel high, and (4) 4 wheel low.  Ford has only three, (1) Auto 4 wheel (2) 4 wheel high (3) and 4 wheel low.
Which would you choose for best gas milage?  Which would you choose for hauling  a trailer (2500 lbs)?  

Answer
Hi Martin and thanks for the question.  Without further info about the two vehicles I would assume the Ford has AWD(All Wheel Drive) while the Chev has 4WD(Four Wheel Drive).  If this is true the Ford would not have a 2 wheel high as the automatic function takes care of that.  The other settings are primarily for unusual conditions and would probably not be used on a routine basis.  Best of Luck and a Happy New Year to you.  Bud