V8 To V4 Question On 2007

Storm Grey · May 8, 2008

On a 2007 1500 Silverado is there anyway to change it so it does not kick to V4 at all? With new exhaust system it sounds great till it kicks to V4, then it kind of has a flutter. I don't see that much of an improvement in the mpg with the V4 mode either. I would like to just shut that off if possible.

Thanks in advance!

hubbycap · May 8, 2008

I don't have one, but the AFM can be turned off with a custom tune.

stlavsa · May 8, 2008

On a 2007 1500 Silverado is there anyway to change it so it does not kick to V4 at all? With new exhaust system it sounds great till it kicks to V4, then it kind of has a flutter. I don't see that much of an improvement in the mpg with the V4 mode either. I would like to just shut that off if possible.

Thanks in advance!

Probably going to need a tune to do that. Would have set the max tps% for DoD to 0% and that would do it. there may be other ways too but thats 1 way of doing it.

nbscanuck · May 8, 2008

DiabloSport Predator handheld programmer can shut it off.

Paul58 · May 8, 2008

DiabloSport Predator handheld programmer can shut it off.

Will it increase the amount of time it stays in V4 mode? There are time when I'm cruising at highway speeds that it would be nice to have a bit more aggressive percentange that it stays in V4, like slight inclines that kick it into V8 and then it pops back to V4 seconds later once you've crested the rise. Surely V4 has enough power for those slight deviation in an otherwise flat stretch of highway!

Texsrt4 · May 9, 2008

hptuners can turn off the DoD settings or can adjust them to suit your needs. personally, i love having DoD. i get an average of 25 mpg on the freeway with my crewcab!!! its great. plus i dont have any flutter or odd sounding exhaust because i am running the corsa exhaust which is all but silent unless you are wide open.

expect to loose an average of 2mpg by turning off the AFM, and you will need to either find a tuner that can shut it off or get a custom tune and make a little more power while you are at it

nbscanuck · May 9, 2008

Diablo doesn't change factory settings when it is on. You just have an off and on setting.

Texsrt4 · May 9, 2008

that seems like such a waste. the benefit of having the DoD is the awesome fuel mileage. who cares if you get more power, if you cant get better mileage with it?

nbscanuck · May 9, 2008

I've found that if you are doing short trips or in the city, it doesn't help alot. The longer the trip the bigger the gains in mileage. I've done the same trip with DOD on and off, pretty much same weather and over the 300 miles it was good for 2.5 mpg. So I'm leaving it on. I didn't buy the truck for its mileage capabilities (I traded in a Saturn Vue that got 35 MPG). Its my choice to leave it on just like its Storm's choice to turn it off.

cdmm151 · May 9, 2008

hptuners can turn off the DoD settings or can adjust them to suit your needs. personally, i love having DoD. i get an average of 25 mpg on the freeway with my crewcab!!! its great. plus i dont have any flutter or odd sounding exhaust because i am running the corsa exhaust which is all but silent unless you are wide open.

expect to loose an average of 2mpg by turning off the AFM, and you will need to either find a tuner that can shut it off or get a custom tune and make a little more power while you are at it

Texsrt4, what setting above GM's did you set the throttle %? I would like to increase the V4 mode myself. Did it increase the MPG's? I am getting around 18 on the highway in my 2008 silverado 4x4 crew cab staying around 65 MPH.

slimjim2525 · May 9, 2008

hptuners can turn off the DoD settings or can adjust them to suit your needs. personally, i love having DoD. i get an average of 25 mpg on the freeway with my crewcab!!! its great. plus i dont have any flutter or odd sounding exhaust because i am running the corsa exhaust which is all but silent unless you are wide open.

expect to loose an average of 2mpg by turning off the AFM, and you will need to either find a tuner that can shut it off or get a custom tune and make a little more power while you are at it

25 mpg in a full size truck, no way. I don't think anyone can believe that.

Texsrt4 · May 10, 2008

hptuners can turn off the DoD settings or can adjust them to suit your needs. personally, i love having DoD. i get an average of 25 mpg on the freeway with my crewcab!!! its great. plus i dont have any flutter or odd sounding exhaust because i am running the corsa exhaust which is all but silent unless you are wide open.

expect to loose an average of 2mpg by turning off the AFM, and you will need to either find a tuner that can shut it off or get a custom tune and make a little more power while you are at it

Texsrt4, what setting above GM's did you set the throttle %? I would like to increase the V4 mode myself. Did it increase the MPG's? I am getting around 18 on the highway in my 2008 silverado 4x4 crew cab staying around 65 MPH.

factory setting is 6% throttle, my current setting is 20% throttle. i also had to add a couple degrees of timing to both the low and the high octane 4cyl timing maps to get it to maintain speed in 4cyl mode.

Texsrt4 · May 10, 2008

expect to loose an average of 2mpg by turning off the AFM, and you will need to either find a tuner that can shut it off or get a custom tune and make a little more power while you are at it 25 mpg in a full size truck, no way. I don't think anyone can believe that.

really, why not? what incentive do i have to come on here and lie to you all about the mileage im getting? further more, what credentials do you have, to inform me that i am wrong? are you an engineer? tuner? mechanic? anything that would lend some sort of credibility to the claim that you are making, that im lying to everyone here? you state that i have no idea what i am talking about, and then you make a claim about the mileage you will see by getting rid of the afm.

see, here is the deal. i am a dyno tuner by trade. i have full access to a shop, a dynojet dyno, and all the tools/software necessary to properly setup and tune a vehicle. it all has to come down to efficiencies, fuel flow, VE's, motor size, etc. no one questions a honda civic getting 35mpg on the freeway with a 4cyl. why would it be hard to think that while cruising on the freeway i get 25mpg with a 4cyl?

if you note what we are talking about, it is light cruise, almost no load on the motor. there is no reason that you need 325cubic inches and 315hp pushing you forward when you are cruising. no, infact 153 cubic inches do just fine. you step down on the throttle and it kicks into v8 mode just dandy. but that isnt so good for the mileage.

if you have hptuners so that you can look at the tune of your truck, i can send you mine for comparison. i dont mind sharing.

cerbomark · May 10, 2008

Just had a EFI live tune and finnally tuned to AFM off. I tried to get used to it but couldn t. Alls the tuner does is select NO under the ECM section for that and it s off. I see no gains with it cause mine never would hold the 4 cyl setting very long. The tuner did say he can make the 4 cyl mode more aggressive and that might help if you are looking for another MPG. With that said , I live in a very hilly area and on the way home with the tune and a Varram intake , Highway only 60 MPH for 30 plus miles I got 19.6 MPG s. The last 7 miles home is uphill and my average dropped down to 18 MPgs. Thats with 4.10 s and 20 in wheels. Never got much better mileage with the AFM on.

Texsrt4 · May 10, 2008

yeah, the stock setting isnt great, like i said its 6% throttle. thats why you kick it up to a more reasonable driving spec. however, thats not enough. the secret to tuning it is 4cyl timing