quick tacoma 4x4 question

hi, i am interested in the 4x4 truck, but i am wondering, is there no way to switch off 4x4 mode? It seems everywhere i read people say that it reduces gas mileage and produced wear of more parts.

i always thought this was kind of a "button" feature and you could turn it off/on at anytime.

if so then wouldnt the gas mileage not be impacted this way? nor the wear on the extra parts?

 

You have a 4x4 button or hubs that you can turn off at any time. However you do have more parts in the fron end that are going to be constantly moving like cv's. As for gas mileage I am getiting with my 3.4L v6 about 20.5 mpg on highway and 18.5 mpg in the city. But 4wd is not constantly engauged.