I noticed after driving my Tahoe without the third row seat(removed), it goes into V4 and autostop modes much quicker and easier.(they are considerably heavy)

has anyone compared the mileage with and without third row seat?
I need more time to compare results.

any feedback is appreictaed.

 

I tried to put the tranny on 2hi vs 4 auto and noticed hardly any difference in mileage. I just kept in 4auto then. with the kids, I prefer to keep the third row.

 

When I bought my yukon he specifically told me to not drive in 4 auto UNLESS you are in conditions that warrant the use of 4 WD as it can prematurely cause trans damage.

I NEVER run mine in 4 auto.....

 

4 auto isn't 4hi. the dealership told me that is the way to do it. my selector has: 2hi-4auto-4hi-4lo..N. tried doing it in 2hi but did not notice any difference in mileage except that the steering effort is less.

 

4 Auto is similar to the old school method of having front hubs locked but not shifting the transfer case into gear yet. The front driveline is ready, axle and differential. There will be some bearing loss. The transfer case front output clutch can engage in about 0.25 seconds when needed.

So Auto is convienient but I find it costs me 1 mpg. And I usually left my hubs un-locked.

That is so 1975.

 

you are right about 2hi being 1975 technology where you have to get out of the car and adjust the hub to 4hi or 4lo or free. the 4 auto should not confused with 4hi since it is like a computerized center differential that translate power to the front wheels when it needs to.

 

I have never had rear seats in and get 21-22 mpg.

 

I use 4 auto a lot when driving through snowy mountains. It makes no sense to me to use it when driving around town.

 

Thanks al, and all for the feedback