I have a question for owners of F-150s with 4.2 V-6 and 5 speed trans.

I bought one a few months ago ('97), nice truck I like it.
I plan on keeping it.

Mine has the 19 code axle (3:55). It has plenty of power but the mileage isn't so hot. I am thinking about swaping to a 3:08 ratio (code 18).
I don't really need the power and would like the mileage.

My question is which rear end ratio do you have and what's your typical mileage?

I am just trying to figure if it's worth the trouble to change rear gears and spedo stuff.

 

I had a 2000 model same setup; 5 Speed w/ 3.55 rear end.
Avg city - approx 15/16 mpg
Avg Interstate - avergae 18/20 depending on how fast I drove.

My2005 with 4.2, 3.55 rear end and auto transmission gets about 1 mpg better both city and interstate: 16/17 and 19/21.

There are a few threads in the 4.2 forum on this subject.

I can't see a gear swap being worth it unless you are getting REALLY bad mpg. If you are, I'd figure something is wrong.

 

I have a 2000 F-150 4.2/ 5-speed regular cab with the 3.55 rear end. I get 16 mpg no matter what.
-Matt