Afm Control

[CajunGTO]

I have a NBS 07 Sierra with the 5.3 AFM system...I have noticed since installing the DIC the 4 cylinder mode switches back to 8 cylinder mode often... Does anyone make a programmer that would hold the 4 cylinder mode longer or limit the sensitivity to switch from 4 to 8 cylinder mode? I know this would greatly increase the mpg.

[Jameson]

I doubt it, but you can get a custom tune to completely remove the 4cyl mode. So who knows what can be done.

[Ranger]

I doubt it, but you can get a custom tune to completely remove the 4cyl mode. So who knows what can be done.

 

He wanted to know if there was a way to keep it in the 4 cylinder mode longer than just when you take your foot off the gas, not get rid of it entirely.

 

Seems that mine stays in 8 cylinder mode other than when I decelerate...It will do it more often if I have it on cruise though.

[FREAKENHYE]

I have a NBS 07 Sierra with the 5.3 AFM system...I have noticed since installing the DIC the 4 cylinder mode switches back to 8 cylinder mode often... Does anyone make a programmer that would hold the 4 cylinder mode longer or limit the sensitivity to switch from 4 to 8 cylinder mode? I know this would greatly increase the mpg.

 

 

This is currently under investigation, I have hptuners and am currently trying to figure it out.

[FREAKENHYE]

I hope this helps, im gonna do the same thing and see if it improves.

 

This is from hptuners site.

 

 

after tweaking the setpoint TPS% to about 20% under low load, i average 24-25mpg on the freeway (according to both my "average" and "instant" gas mileage settings on the DIC)...thats at 70mph!!!!!!

 

while driving around the city, its the same as any other v8 truck

[MS3DALE]

after tweaking the setpoint TPS% to about 20% under low load, i average 24-25mpg on the freeway (according to both my "average" and "instant" gas mileage settings on the DIC)...thats at 70mph!!!!!!

 

while driving around the city, its the same as any other v8 truck

 

Now I like that!!! 24-25mpg....Hell yea!!!

[NathanL]

I've been average about 15.5mpg on nearly 100% highway at 75mph with cruise set on pretty flat land.

 

I'm wondering if there's different sets of programs in there by different build dates. On some sites I hear guys say theirs says v4 mode a lot.

 

Mine will only say it when I'm going downhill or have my foot off the gas.

 

Today while on flat flat flat ground I had it on nearly 80 and my deal said v8 mode the whole time and 12mpg.

[FREAKENHYE]

I've been average about 15.5mpg on nearly 100% highway at 75mph with cruise set on pretty flat land.

 

I'm wondering if there's different sets of programs in there by different build dates. On some sites I hear guys say theirs says v4 mode a lot.

 

Mine will only say it when I'm going downhill or have my foot off the gas.

 

Today while on flat flat flat ground I had it on nearly 80 and my deal said v8 mode the whole time and 12mpg.

 

 

Anything over 65 in these bricks is not MPG wise. Set it at 65 and see what it does. What do you have?

[NathanL]

I've been average about 15.5mpg on nearly 100% highway at 75mph with cruise set on pretty flat land.

 

I'm wondering if there's different sets of programs in there by different build dates. On some sites I hear guys say theirs says v4 mode a lot.

 

Mine will only say it when I'm going downhill or have my foot off the gas.

 

Today while on flat flat flat ground I had it on nearly 80 and my deal said v8 mode the whole time and 12mpg.

 

 

Anything over 65 in these bricks is not MPG wise. Set it at 65 and see what it does. What do you have?

 

 

At 65 I'd never get anywhere. Speed limit here is 70 anywhere outside the city limits and many roads are 85.

 

I don't really care about the mileage but from what I read you could have got the same trim truck in an '07 classic and a NNBS '07 with the same engine and the classic gets better mileage even with the new one having AFM etc...

 

I wonder what speed they test the trucks to get the sticker on 55? My truck was listed at 16/20 and I can't hit 20 on my instant mileage deal unless I'm off the gas AND heading downhill.

[FREAKENHYE]

I've been average about 15.5mpg on nearly 100% highway at 75mph with cruise set on pretty flat land.

 

I'm wondering if there's different sets of programs in there by different build dates. On some sites I hear guys say theirs says v4 mode a lot.

 

Mine will only say it when I'm going downhill or have my foot off the gas.

 

Today while on flat flat flat ground I had it on nearly 80 and my deal said v8 mode the whole time and 12mpg.

 

 

Anything over 65 in these bricks is not MPG wise. Set it at 65 and see what it does. What do you have?

 

 

At 65 I'd never get anywhere. Speed limit here is 70 anywhere outside the city limits and many roads are 85.

 

I don't really care about the mileage but from what I read you could have got the same trim truck in an '07 classic and a NNBS '07 with the same engine and the classic gets better mileage even with the new one having AFM etc...

 

I wonder what speed they test the trucks to get the sticker on 55? My truck was listed at 16/20 and I can't hit 20 on my instant mileage deal unless I'm off the gas AND heading downhill.

 

 

Whats your trim level and what do you have. I know these trucks are set for afm at 65 maybe we need to rais yours or take back to the dealer to have them raise it.

[NathanL]

'07 5.3 Silverado LT 4wd. Make sense that it's set at 65 - that's why I notice it never comes on because I never drive slower than 65 on the highway - come to think of it I don't know anyone who drives less than 65 on the highway.

 

Not really worried about it tho.

[FREAKENHYE]

'07 5.3 Silverado LT 4wd. Make sense that it's set at 65 - that's why I notice it never comes on because I never drive slower than 65 on the highway - come to think of it I don't know anyone who drives less than 65 on the highway.

 

Not really worried about it tho.

 

 

Try this for me try going 65 and see what it does, it should improve,

[iminaquagmire]

In my 5.3, tow/haul mode keeps it in V4 mode more at cruising speed. City makes it worse. With tow/haul on, I can keep it in V4 with slight acceleration. Its a double edged sword though becuase there is a fine line between where it helps and where it drops the mpg.

 

Another tip, 3rd gear seems to drop a lot of TM. If I want to get off the line faster, I drop it in third and away I go. I end up doing this more frequently than I'd like just because the truck is so bad off the line. If I don't, I end up impeding traffic. Its embarassingly slow and my exhaust only makes it seem like I'm really getting into the trottle for no speed. Hopefully I'll be getting a dyno tune in the next month or so.