V4 - v8

[2 E L O]

A 3-4mpg or 15-25% increase in fuel economy with a handheld tuner is total bull. Even the best custom tunes won't net that kind of improvement.

Ugg...come on, people........

 

[01HDtahoeNJN]

I've noticed that mine stays at 4cly in town when going 30 on a flat surface and going 55 or under on a flat surface on the highway. The problem is you won;t catch me doing either! HAHA!!!

Lololol that's great!


Sent from my SCH-I500 using Tapatalk

 

[felixgun]

that's something to look forward too since I'll be doing exhaust before the tune....

Airaid CAI/Magnaflow muffler recently added and now I too am experiencing this.. next on the list is def BB tune...

---------- Post added at 01:15 PM ---------- Previous post was at 01:10 PM ----------

No, I drive the same. I don't have to push on the gas as much

Do you have an intake/muffler along with the tune? or you just have your stock everything, plugged in the diablo, and bam 4-5 MPG increase? It sounds too good to be true. I am getting 14/17 city/highway so i'm guessing you would get that stock too. What are your current readings? I'm interested

 

[emann_01]

Do you have an intake/muffler along with the tune? or you just have your stock everything, plugged in the diablo, and bam 4-5 MPG increase? It sounds too good to be true. I am getting 14/17 city/highway so i'm guessing you would get that stock too. What are your current readings? I'm interested

it sounds too good to be true because it is

 

[07Burb]

Do you have an intake/muffler along with the tune? or you just have your stock everything, plugged in the diablo, and bam 4-5 MPG increase? It sounds too good to be true. I am getting 14/17 city/highway so i'm guessing you would get that stock too. What are your current readings? I'm interested

it sounds too good to be true because it is

 

[04ctd]

i notice if you are using the gas pedal, it does not do V4 much.

but if I set the cruise, it usually falls into V4 within ~15 seconds.

i think the cruise tells the ECM that "hey, we are not gonna be accelerating soon, how about relaxing and kicking 4 cylinders off for some MPG"

i think if the ECM tries to predict when it should go V4, you may tap the pedal, and make it not go into V4.

i think the cruise is the key. if you think about my drive to work, it's 30 minutes.

V8 is ~18 mpg on the "instant MPG" guess-o-meter
V4 is ~30 mpg.

so, basically, you need to be on the cruise for more than 50% of the time, in order to bring up the "average" to closer to the 30,

i think setting the cruise tells the algorithm to go ahead and decide to drop it in V4
the earlier it drops in, the more time you have at ~30 mpg

people in my area speed so much, that if you set the cruise to the speed limit, everyone pretty much walks away from you, and you cruise right along.

i have found the 07 will set as low as 25mph. thats crazy, but we have a ~2 mile stretch of 25mph, that drops right into V4 with cruise

a good strong headwind will knock it back into V8 though.
any uphill
any strain on the "brick"

it's a numbers game: keeping the cruise set over 50% of the time is what i want to do and hand calc my mileage for a full tank.

 

[phileaglesfan]

so why doesnt a BB tune do the same??? If a hand held generalized "tune" can do it then why wont a custom tune that is adjusted based specifically on your engine?

Also, BB will sell you a spare ECM and TCM...just swap them before a dealership trip and no worries. And dont forget that GM has to PROVE to you that the modification that you have done is directly the cause of the problem

There was a TSB out about GM checking the tune that is loaded versus what is history. The link is below. No matter what you do you won't be able to get the numbers to match if the tune has been changed.

GM doesn't have to prove anything also. It will be up to you to prove that the tune didn't cause say a lifter to fail. You won't be able to. GM has lawyers on standby to fight these type of things and has been thru it many times.

Post 2 on this link has an attachment that is too big to attach here. http://forums.corvetteforum.com/c6-...-gm-response-to-aftermarket-calibrations.html

It isn't up to the dealer to decide any more however if they prove that the tune has been changed and not by them your powertrain warranty is gone.

 

[emann_01]

i notice if you are using the gas pedal, it does not do V4 much.

but if I set the cruise, it usually falls into V4 within ~15 seconds.

i think the cruise tells the ECM that "hey, we are not gonna be accelerating soon, how about relaxing and kicking 4 cylinders off for some MPG"

i think if the ECM tries to predict when it should go V4, you may tap the pedal, and make it not go into V4.

i think the cruise is the key. if you think about my drive to work, it's 30 minutes.

V8 is ~18 mpg on the "instant MPG" guess-o-meter
V4 is ~30 mpg.

so, basically, you need to be on the cruise for more than 50% of the time, in order to bring up the "average" to closer to the 30,

i think setting the cruise tells the algorithm to go ahead and decide to drop it in V4
the earlier it drops in, the more time you have at ~30 mpg

people in my area speed so much, that if you set the cruise to the speed limit, everyone pretty much walks away from you, and you cruise right along.

i have found the 07 will set as low as 25mph. thats crazy, but we have a ~2 mile stretch of 25mph, that drops right into V4 with cruise

a good strong headwind will knock it back into V8 though.
any uphill
any strain on the "brick"

it's a numbers game: keeping the cruise set over 50% of the time is what i want to do and hand calc my mileage for a full tank.

thats a great explanation but the v4 mode is simply based on engine load while over a certain speed/rpm

i think its 40% of the engine load, not sure what the mph/rpm requirement is

---------- Post added at 11:41 PM ---------- Previous post was at 11:31 PM ----------

There was a TSB out about GM checking the tune that is loaded versus what is history. The link is below. No matter what you do you won't be able to get the numbers to match if the tune has been changed.

GM doesn't have to prove anything also. It will be up to you to prove that the tune didn't cause say a lifter to fail. You won't be able to. GM has lawyers on standby to fight these type of things and has been thru it many times.

Post 2 on this link has an attachment that is too big to attach here. http://forums.corvetteforum.com/c6-...-gm-response-to-aftermarket-calibrations.html

It isn't up to the dealer to decide any more however if they prove that the tune has been changed and not by them your powertrain warranty is gone.

I dont think you understand my meaning of "spare" ECM/TCM. BB sells the spare one to you with a stock file on it...you install it and then have it tuned. The original stock ECM/TCM just sits in the console until i need to swap them back. No files have been touched on my original stock ECM/TCM.

Also, thats a great GM "policy" but i think a federal law trumps it...

http://www.impalaclub.com/naisso/magmoss.htm

You can read about it almost anywhere....a dealership has to PROVE that your aftermarket part DIRECTLY caused the failure. Obviously, with an internal engine/transmission part failure and you have messed with stock cal files you don't have much of a chance. But if there is no trace of cal files being changed...

 

[phileaglesfan]

You can change the ECM all you want since the code is not part of it. Modify the ECM and the code is modified.

The MMA is also 36 years old. The dealer would laugh you out of the building if you mentioned that (I'm sure someone mentioned it before).

 

[07Burb]

The MMA is also 36 years old.