does removing afm just eliminate 6th gear

[Slo281]

Is that what happens or is their more to it

[05cyclone]

No it just keeps the truck from going into v4 mode.

[newdude]

No. Turning AFM off just turns AFM off. That is if you are tuning/Range AFM delete. If you want to disable AFM on the fly while driving, if you take the shifter and put it in to M and then take the up/down toggle and set it to 5, it locks out 6th and turns AFM off.

[TJay74]

Correct, as everyone has said. If you are turning AFM off thru tuning all it does is stops you from going into V4 mode. I tuned mine out 3 months after I got the truck. It would never go into V4 mode anyways and when it did it was only for maybe 10 seconds.

[Slo281]

Thanks for the clarification guys

[gone_fishing]

Basically any manual gear except M6 will disable V4 mode.

[nadrojcote]

How much of an effect does afm actually have on mpg anyways? I would assume the benefits of a tune would equal out to be about the same mileage?

[Trza]

I went on a 1000 km road trip this weekend and kept an eye on the AFM. Since this was the first time since owning the truck that I had the opportunity to hit the highway, I kept an eye on the V4 mode to see how much it would kick in. Speed limit was 110 km/h so I set it between 115 km/h to 125 km/h depending on traffic flow...the only time it kicked in was going downhill.

 

In the city it is also a non factor...I can't see where the AFM can even benefit fuel economy with the way it is currently programmed.

[nadrojcote]

Mine is almost always in v4 in the city and the same on the highway only when going down hill.

[Slo281]

How much of an effect does afm actually have on mpg anyways? I would assume the benefits of a tune would equal out to be about the same mileage?

Have noticed a drop in mpg. Nothing significant yet but it has dropped.