2WD or AUTO for better MPG?

[robgreg75]

Always use 2wd unless it is bad weather. Actually I never use the Auto in any of the 3 Tahoes I have owened. I use 2wd or 4wd when needed, auto was only for when my wife was driving in bad weather and I was afraid she would forget to switch back to 2wd. My ex once left my older tahoe in Auto after crappy weather and she was complaining it seemed funny on the highway. Ya there are more components spinning in Auto it just isn't fully engaged.

 

[Hobert]

I used auto once in my 2001 yukon XL. Hydroplane city, was dangerous on the highway at speed in a rainstorm. From then on and with new suburban 2wd of 4wd high and low as required.

 

[TollKeeper]

I have pretty much only ever used A4WD, although this is on my Envoy V8. This way I can pay attention to the other idiots on the road, and not when I need to turn off the 4WD. Only times I have ever used 4WD mode is when my neighbor got stuck in front of my house in his 4wd F150.

 

[Knagawa350]

2WD should be better. I don’t know the specifics but it engages the 4WD components but doesn’t actually send power to the front wheels until it senses slippage of some type (it’s more of a standby 4WD configuration where it’s ready to go until needed).

If you’re not driving on snow or a heavy downpour that might result in hydroplaning, it’s probably less wear and tear to leave it in 2WD until those conditions occur. The manual does a good job of explaining the differences between the modes.

I haven’t ran my ‘21 in Auto yet but would guess it should be similar to my ‘07 where it would get worse gas mileage in auto compared to 2WD. I don’t think it was that worse…maybe 2-3 gallon per mile difference.

You had a 2007 hybrid or just 5.3? I’m mid project on rebuilding the 2ml70 transmission on the 2009 I just bought. Had some random ownership questions (hybrid related) if you don’t mind.