Looking at window stickers of vehicles with full time 4wd and part time 4wd there is reduced mpg with the full time transfer case.

 

Looking at window stickers of vehicles with full time 4wd and part time 4wd there is reduced mpg with the full time transfer case.

Exactly! Full time 4wd may drive all four wheels at the same time, so fuel mileage can suffer. But some systems apportion power to the secondary axle only as needed, and may be in 2wd mode a lot of the time.

But either way the old school system is best for serious off road traction and full time is best for peace of mind in normal driving. You pay a small price in fuel economy with full time AWD, but a lot of drivers really like the added security.

 

My former Frontier only disconnected the front axle at the transfer case leaving the hubs, cross shafts, and front driveshaft spinning with the tires. All those rotating parts similar to full-time 4WD.

My F150 disconnects the front drive at the transfer case and the wheel hubs.

 

Yeah - every manufacturer does it differently and there is no one size fits all answer to that question.

 

Not getting into all the "technical mumbo-jumbo" about 4WD. Common sense tell cannot be driven in "full time 4WD" on dry payment all the time. Mostly loose ground, off road.

 

Full time 4WD vehicles do have a center differential and they can be driven on pavement. It is not mumbo-jumbo but just a different way to drive a four wheels on or off road.

 

I learn something. I owned 2 Toyota 4x4 pickups. Never cared for other brands.

 

Me too - Toyota all the way.

Full time 4WD is a newer thing and not something that Toyota has offered AFAIK.