Yep, you can definitely switch modes going down the road, even at highway speed, just not to 4-low. Even in the summer if you’re on an interstate at speed and it starts raining switch over to 4-hi to make sure your truck stays facing the right way! When you get back to dry road go back to 2-hi so you’re not tearing through as much fuel (and to save needless wear on the transfer case)

AUTO is effectively AWD. Safe to use anywhere, but pulls a bit more fuel. You'll notice a bit less wheel skitter on acceleration on iffy/gravely/slick surfaces.

Since the late eighties they came out with shift on the fly that's what makes it where you could put it in for high up to 50 miles an hour for low you have to come to a stop put it in neutral

Thanks good info..

This vidéo help me a lot tks .good job

Excellent

Great information ( if I ever buy a Yukon Denali ) I'm considering the 6.2 and the diesel - my one concern is when the engine is in regeneration mode . . . have you ever had to wait for it to finish regen before turning the engine off ? I drove a new commercial vehicle ( before retiring ) with a diesel engine, and I was told not to turn it off when it was in regen mode - a real pain to have to wait in a parking lot before I could go into a store !!! I will be doing almost all driving around town, for very short trips ( less than five miles ) How often does your diesel go into regen mode ? The one I drove, eight years ago, did it at least once a day ( I drove it for four hours in the morning and four in the afternoon ). VERY few people on KZfaq have talked about the diesel in the Yukons regen mode.

Only 4Lo require you to stop and switch to neutral and it’s only for off-road or extreme heavy snow in low speed. Use auto for rainy or snowy conditions. 4WD high should only be used if the road is slippery only in rain or slippery conditions. Terrain mode is different it controls ur engine torque different. So it’s not the same as transfer case.

Do not shift into 4wd if the back tires are spinning or slipping in 2wd or rwd. You'll break something.

I’m sorry…. But a 2wd rear drive is both wheels moving not one…it’s not 1wd.