XLR8NSS

iTrader: (4)

Check this out. I asked over on EFILives website a while back about editing the AFM parameters in the computer. Post #21 has the actual link to the thread. I imagine a few little tweaks could keep it in V4 mode longer but, I don't think it's really supposed to stay in V4 mode for too long judging by some of those parameters.

https://www.performancetrucks.net/fo...&highlight=AFM

Chevy Cowboy

iTrader: (5)

so no one is actually getting the advertised mileage?

toneloc12345

It's not supposed to be in V4 mode when there is any load on the engine. All of the gas savings are at idle and coasting.....

niugnep

Not true, at idle it goes back to V8 mode...usually goes V4 to V8 about 20mph as I slow down. At idle it stays in V8.(I was wondering why too, perhaps for cooling, electrical load, balance or so its ready to load off idle?). My truck will stay in V4 at 110km/hr (about 68mph) on level highway driving, shows 9L/100km reading or about 32 mpg (Imp gallons or about 26US gallons) at that speed. Probably go back to V8 any faster (truck still only has 300 miles on it) or on hills etc of course.

And of course any time you step on the throttle it goes to v8, its for cruise, coasting, slower speeds and lightly loaded vehicles.

5.3 RCSB 2WD.

circusboy

iTrader: (2)

I just checked mine today. 14.55 MPG. That was with a lot of spirited city driving. Truck has 516 miles on it now. I scooted the seat further back to keep me from smashing the pedal so much, lol. I hope it gets better than this. Probably just me.

4.8bowtie

my elevation is anywhere from 1000 to 4000, but is continuosly up and down. very little flat ground round here. i also noticed while sitting still or in park it idles in v8 mode. alot of my problem is when i floor it and it shows 3mpg.oh well, the trade off for power. i must say i think my old 4.8 would outrun this 6.0. im not impressed at all. but of course i had a few mods done to the last truck and the 6.0 is stock for now.

niugnep

I'm wondering if GM holds back the engines until a certain mileage is up? My 97 WS6 seemed like someone flipped a switch when I hit 3000miles and others reported the same...and the 6.0 has lots of torque limiting programming off the line too.

Hopefully wakes up and better mileage with more miles on it....