[bakawaka]

I have a 2015 Escalade (not the ESV). It seems to drive better in auto 4WD. On a very long highway trip of 4,000 miles, I was driving 80 MPH (speed limit of 75 MPH). The front wheels had a strange whirring/whistling sound that was very annoying. I switched to 2WD and the noise went away. I switched back to auto 4WD and the annoying noise returned. So here are my questions:

(1) does it harm the vehicle to keep it in auto 4WD? This is my preference because the vehicle does seem to drive better in this setting.

(2) does anyone else get the strange whirring/whistling noise at high speed when using auto 4WD? does the noise mean that the vehicle is somehow being harmed by the use of auto 4WD?

 

[JCM1]

You're not harming anything by driving in Auto 4WD if you prefer. The whirring noise you're hearing is due to the front hubs being engaged when you drive in the Auto 4WD. You can drive like this on dry pavement however there is no added benefit. Theoretically, you are adding additional wear to the front hubs and losing maybe 1 MPG due to the additional resistance in turning the hubs. As far as why it seems to drive better, I'm not sure. It is possible the added resistance turning the front wheels may make it seem "tighter" through the steering wheel however, I've never personally observed this with any of GM's Auto 4WD.

 

[blit184]

There is a some difference in sound when you place the vehicle in auto 4WD.....at least I think it "some" but noticeable.....what it is , is the "transfer case" coming alive when the AUTO system is activated....it means that various components are now "spinning" in preparation for sending power to the front wheels if needed. A change is sound is normal.....running in Auto 4WD will NOT harm the vehicle. All that being said..... I would not run in AUTO 4WD all the time simply because there is NO difference in handling in non-bad road conditions.. and.... there is a better fuel mileage figure if you stay in 2WD.

 

[evois]

coming from the same 4wd system that my escalade hybrid had as well as electric power steering, I agree the 4auto drives and handles better esp if you get rain slick conditions. the steering tightens too compared to 2wd. it will not cause any wear even in 4auto as evidenced by my escalade hybrid's 195k miles when I traded it for the 2015i