Active fuel management mods?

[totheyard]

I did a search in regards to AFM and found a lot of posts. I could not find any that used a tune to cancel/ modify the AFM. We bought the wife a new Yukon and she is stating the V4 switch to V8 is a firm shutter. From cruising 40-45 mph to a stop light. I have not driven the truck in a couple weeks, so I am going off her statements. Can I modify/ cancel the AFM and will it effect MPG that much? I have a feeling that AFM does not save the 6.2 that much gas.
Thank you!

 

[skippy737]

I wish we could select either 4 or 8 cyl mode all the time.
4cyl for city amd 8 cyl for towing or hauling people.

 

[07Burb]

Black bear tune is your answer

 

[totheyard]

Skippy,
I don't know what year your truck is, but is your AFM shutter getting better or worse?

---------- Post added at 10:32 AM ---------- Previous post was at 10:30 AM ----------

Burb,
Do you have any experience with modifying the AFM?

 

[skippy737]

I have a 2010 denali with 9450 miles. I cant say one way or the other, bc im sensitive on the throttle, i can always tell/ feel it. Its obviously more noticeable going from 4 to 8 then vice versa.


Burb, are u telling me, wthat ith a black bear tune, i can select how many cylinders i wish to use manually?

 

[totheyard]

Does a tune shut it off, or just modify when it activates?

 

[domin8]

I'm not sure about Black Bear, but I do know that with HP Tuners my tuner was only able to adjust throttle percentage for when AFM turned on/off. We played with a bit and didn't really notice any difference, so I went back to the stock settings.

One thing to consider before messing around with the AFM is the engine oil consumption issue these trucks seem to be having. IMO, it's solveable by turning off the AFM and just running as a V8 all the time.

 

[totheyard]

How much mpg loss in the V8 mode only (AFM off)? Why does it burn oil?

 

[07Burb]

bb tune can turn AFM off with I prefer.

 

[soulsea]

BB shut mine off as part of my tune ... I lost very little efficiency because of the road conditions I drive in most of the time, but if you do a lot of highway driving on flat roads then the difference will be more significant.