Originally Posted by Toreador4x4
yes it definately does hurt mileage.
with my hubs unlocked i got 18.5 driving to grand rapids from livonia, on my way back hubs locked in i got 15
Something else cause the mileage drop or something is wrong with your truck.
I had AVM hubs on my 98 and got 14-15mpg no matter what. If I locked the hubs (as I did for months at a time) I would see a 1 mpg drop at the most.
2000.5 and newer rangers have live axles (engaged all the time). So do 01-05 sport tracs, 95-01 explorers, etc.
On the other hand the AVM hubs are nice to have. 2wd low is fun to play with sometimes. And if you break a CV joint you can unlock the hubs and drive it still if you have to. Some people have had them break or fall off, but mine worked well for me. Besides they are cheap and super easy to install. Keep your current modified hubs in the truck as a backup.
I guess even with a 1mpg drop they will eventually pay for themselves...?