Installing front locking hubs, is it possible?

[fernandolpa]

Owning a 2001 AWD with no problems so far. Loved with the car. Only issue nowadays is fuel consumption. In Europe paying more than 2 USD per liter (more than 8 USD per gallon), using the car is like a luxury driving.

So I was wondering how to improve MPG. Why to be using front transmission while is not necessary? Could be possible to disconnect FWD (or RWD) to save fuel? So I remember the first AWD and 4x4 that they had the front locking hubs on the wheels. Could be possible to do it in our AWD RX?

Anybody has a better idea? Don't tell me to change the car, is not gonna happen. I have other two for the daily use. I would like to improve consumption by at least 30% (dreamer...)