Usinng the drive selector switch on AUTO vs 4x2 on a 2001 Pathfinder LE. Milage affect?

Leave it in auto all the time. The only time the 4X4 will be activated in auto mode is when traction loss is detected. Otherwise, it will by default run in 4X2 mode.

Yeh but it still engages the front axle reducing fuel milage.

Actually, the front axles are turning all the time anyway. The controlling occurs at the transfer case. Are you sure you know more about Nissans than a fry tech? Perhaps you should do a little research before you insert your foot in your mouth.

Gord,

I think that if it's in 4x4, it's always driving all four wheels. If it's in 4x2, it will drive only the back wheels regardless of the circumstances. In AUTO, it will drive only the back wheels until it detects slippage, then it will automatically engage the front wheels. Since whenever it's in 4wd, it will use more gas than in 2wd, this means it will use more gas during the rare times it's in 4wd. But the extra gas will cost less than the possible consequences of losing control!

Does your truck have the fancy All-Mode system like the QX4 has?

The mileage (or power to the wheels) loss will also be greater or lesser depending on whether the front hubs are always engaged or not, and I don't know if they are on the newer PF's. I suspect in AUTO they would be, since it's one less thing to engage and disengage as the need for 4wd comes and goes. So there's a mileage penalty for that.