Afm Take It Or Leave It

Brad0Walker · June 5, 2009

I am in the process of getting a blackbear tune and cannot decide whether i should leave on the AFM or take it off. Can some of you guys who have been tuned tell me your results. 09 with 5.3. I have also heard about this creating some problems with the longevity. Thanks in advance.

Bowtie2Sierra · June 5, 2009

I left AFM alone when Black Bear tuned my truck. I'm indifferent to AFM though. Some guys here have turned AFM off and have noticed little, if any, difference in MPG's. Mine is still seamless so it doesn't bother me.

Regarding longevity, I can't answer that question but I can only assume that it could have an affect long term. Maybe someone else can chime in with that. I really don't keep my vehicles long enough to be concerned with longevity.

y2kz71 · June 5, 2009

turn it off, my 2005 CC got better gas mileage than my 08 RCSB with AFM

VMax2007 · June 5, 2009

OFF WITH IT!!!

No differnce in MPG's with mine off, but I don't drive 55 MPH on the freeway either.

slomo007 · June 5, 2009

OFF WITH IT!!!

No differnce in MPG's with mine off, but I don't drive 55 MPH on the freeway either.

That's interesting Jeff, do you mostly drive highway or city? Aggressive or not aggressive?

I'd turn mine off if I really felt it wasn't helping (and I just sent my modules in to Justin for a re-tune anyways so now is the time to do it) but I drive mostly city and there are a couple stretches of road where I can stay in V4 for a mile or two on the way to work (only an 8 mile drive total one way), so I have to think it's helping. There's only one way to find out I suppose but I'd hate to tell him to turn it off and then have to send them back to him for another retune if my mileage takes a hit.

georgecdisc · June 5, 2009

One day when I get a tune, I plan on leaving the AFM on. If it bothers me I can always get it re-tuned for free. As of right now I generally drive in the 45-55mph range, so I feel it is beneficial.

brims · June 5, 2009

I had my truck tuned. We were on a really crappy freeway that made my truck bounce badly, where the individual pieces of cement come together, so neither of us noticed the truck jamming in and out of V4 mode. When I did notice it on smoother freeway I decided right then to have it turned off. I had to send the computer to him unfortunately, but it will be gone soon, I should have it back Saturday or Monday. It drove me up the wall, there's no way I was able to even go through 1 tank with AFM acting that way.

jrrod2004 · June 5, 2009

OFF WITH IT!!!

No differnce in MPG's with mine off, but I don't drive 55 MPH on the freeway either.

That's interesting Jeff, do you mostly drive highway or city? Aggressive or not aggressive?

I'd turn mine off if I really felt it wasn't helping (and I just sent my modules in to Justin for a re-tune anyways so now is the time to do it) but I drive mostly city and there are a couple stretches of road where I can stay in V4 for a mile or two on the way to work (only an 8 mile drive total one way), so I have to think it's helping. There's only one way to find out I suppose but I'd hate to tell him to turn it off and then have to send them back to him for another retune if my mileage takes a hit.

I drive agressive and think Jeff would fall into the normal/agressive (certainly not grandma)

jnpaddison · June 5, 2009

mymain concern being the continual cycle of activation/deactivation and whats the cost if something goes wrong ,,, which in my luck will probably be more that the saving in gas ..

y2kz71 · June 5, 2009

mymain concern being the continual cycle of activation/deactivation and whats the cost if something goes wrong ,,, which in my luck will probably be more that the saving in gas ..

Thats another concern of mine...long term effects of this.

JokerJ · June 5, 2009

mymain concern being the continual cycle of activation/deactivation and whats the cost if something goes wrong ,,, which in my luck will probably be more that the saving in gas ..

If it happened within 100K miles, the powertrain warranty would cover it. Beyond 100K would be an interesting expense. If you keep it out of overdrive, that pretty much turns it off too, right?

brims · June 5, 2009

mymain concern being the continual cycle of activation/deactivation and whats the cost if something goes wrong ,,, which in my luck will probably be more that the saving in gas ..

If it happened within 100K miles, the powertrain warranty would cover it. Beyond 100K would be an interesting expense. If you keep it out of overdrive, that pretty much turns it off too, right?

No, it will activate in 3rd gear.

Silverado4x4 · June 5, 2009

Mine turns on and off unnoticed so I could really care a less about it. For longevity who knows as I havent heard of any. A service tech friend of mine said if something would happen it would go into default mode which is 8 cylinder mode so dont worry about it being suck in 4 mode if something would happen, that would suck huh.

JokerJ · June 5, 2009

If it happened within 100K miles, the powertrain warranty would cover it. Beyond 100K would be an interesting expense. If you keep it out of overdrive, that pretty much turns it off too, right?

No, it will activate in 3rd gear.

Thanks brims. That's good to know.