AFM Newb question

[Mickey_7106]

How do i know if my truck is equipped with it?

 

[iamdub]

Other than feeling it engage V4 Mode (not everyone can tell), the easiest way is to, while idling, press the DIC control button (top one?) to cycle through the screens until you see one that displays your instant fuel economy. To the right it will say "V8 MODE". Leave it there and drive easily. At a steady speed above ~30MPH, if it displays "V4 MODE", then you have AFM.

DIC control buttons:




V8 MODE:




V4 MODE:

 

[Chrismnj]

From what I understand, all 2007.5 on up trucks with the 5.3L are AFM.

 

[swathdiver]

How do i know if my truck is equipped with it?

What are you driving?

 

[Mickey_7106]

Thanks. I've gone through the DIC menu to "instant economy" while driving at 70mph to see how much i was getting on E85 (11 mpg on mostly flat road) but i didn't notice the "v8 or v4". I drive a '09 yukon xl 4x4

 

[swathdiver]

I drive a '09 yukon xl 4x4

So do I. You should be getting 14 or more at 70 on E85. Lots of things come into play though.

 

[Mickey_7106]

I feel the same way, but i don't drive it enough for it to bother me. I was getting about 15-20mpg on my '06 Silverado CC with all terrain tires and 4 speed trans

So do I. You should be getting 14 or more at 70 on E85. Lots of things come into play though.

 

[swathdiver]

I feel the same way, but i don't drive it enough for it to bother me. I was getting about 15-20mpg on my '06 Silverado CC with all terrain tires and 4 speed trans

Well, it may be a sign of something amiss. I ran 7-11 miles each way for a 2-way average and did it 3-6 times for every 5 mph from 35 to 80. Did not use the instant though, I reset the regular counter for each leg of each run. Did it for gasoline, E85 @ 72%, E85 @ 80% and may soon do it for E30 @ 25%. Also running an AT tire.

 

[Mickey_7106]

I just remembered that i was driving in 4Hi most of my trip due to terrible weather so the 11 mpg is probably the norm

 

[swathdiver]

I just remembered that i was driving in 4Hi most of my trip due to terrible weather so the 11 mpg is probably the norm

Yeah, that'll do it (bad weather and 4x4)! Do you not like 4Auto? I've done both in terrible weather but not sure why I would or should prefer one mode over the other while cruising down the highway.