V4 vs. V8

[73shark]

Well mine doesn't take 12% to go to V8 mode. Just barely touching the throttle takes it out.

 

[ZX1100F1]

Some ECM's are calibrated to take as little as 6% throttle to deactivate V4 mode.

 

[kpanza]

I think everyone expects WAY too much from the AFM technology! Sure, some of it may be due to the GM marketing (and other manufacturers who have similar systems), but this is just another small step towards increasing MPG, not the cure all...

What I am going to try is something a little different. In my driving route, I sit at traffic lights for a lot of the time in city traffic...what I want to try is actually putting the truck in Neutral and shutting OFF the motor while I am waiting for the lights/traffic to start moving. Idling is getting us ZERO miles per gallon...yes, this will add wear and tear to the starter, but I'm not overly concerned, since the truck is still under warranty and it's also a lease...I just want to see what, if any, kind of increase I actually see...I've done it here and there before, but never for a full tank...yeah, you get some looks when you start cranking the motor up at each light, but who cares?

I'll post up my results if I get around to trying it for a full tank during my normal commute routine...anyone else tried this?

 

[73shark]

Just heard that GM is bringing over a European Saturn variant that shifts to neutral when stopped.

 

[Rollin Thunder]

Just heard that GM is bringing over a European Saturn variant that shifts to neutral when stopped.

The acadia and enclave already do that, my parents ones roll back on a hill, you kinda have to power brake it to get it to move with out hitting the dude behind you, that feature is actully very annoying and not worth the risk for what VERY LITTLE gas you save. You can tell as when you hit the gas from a stop it "thinks" for .5 of a second and then goes.

 

[2007TahoeLTZ4x4]

wow that sounds almost dangerous

i agree though...people expect way to much out of afm it would be nice though if some company would make a handheld that would just adjust the amount of throttle input to knock it out of 4cyl mode course im not sure that this is even possible

@ZX..., do you know more specifically which ones are calibrated differently and why?

also does anyone know why tow/haul mode supposedly allows it to stay in 4cyl longer? is the comp increasing the amount of throttle input it takes or just expecting a load or something? also does the tow/haul mode change anything? i would expect firmer shifts ...enlighten me please

 

[Gambler]

also does anyone know why tow/haul mode supposedly allows it to stay in 4cyl longer? is the comp increasing the amount of throttle input it takes or just expecting a load or something? also does the tow/haul mode change anything? i would expect firmer shifts ...enlighten me please

I think it is because the tow haul mode raises the shift points, so if you can manage to stay below the 12% throttle boundary, your shift will happen later thus leaving you in v4 mode longer.

 

[73shark]

Also the tow/haul mode takes it out of OD at low speeds which increases engine rpm and thus more power. Judicious use in town can increase mpg but you have to keep switching in and out.