V4 mode gas mileage?

[GsBowtie]

I know it's off topic but man do I like those Z71 carbon fiber instrument clusters! Sure wish I could swap one in my Sierra. I actually like the ones in the Chevy's better.

Agreed, I really like the carbon fiber dash in my 15 z71. I also like how it says "z71" above the tach.

 

Fwiw, my truck averages 14-15mpg on my mostly back roads, in town commute to work

[oneandzero]

Why anybody would want to turn it off is a mystery to me. It's barely noticeable.

Makes me wonder how my dealer could make the statement that mine was working as designed. Mine was very noticeable when on. In fact my truck vibrated, clunked, chugged and I had the nice exhaust drone noise when AFM was on. Mine would engage in town, on the highway, heck I think it was on more than off. Doing 130 on the 401 it would be on. Really passing every car on the road in AFM mode. I noticed the litres/100 getting better when it switched back to V8 more often then not. Maybe GM needs to educate the dealers that AFM should barely be noticeable I guess. My dealer paid for my tune and mine wasn't the only one. They knew the alternative was me trading the truck. It was a vibrating mess when the AFM was on and I freaken hated it.

Hope that helps solve the mystery and as I stated before my fuel mileage hasn't changed a bit.

[ewbldavis]

Seems each has their own ideas, which is great and what contributes to the quality of the forum.

 

I dunno if I see a difference - average is 18mpg. I do notice a "squeak" when it changes from V4 to V8 (may ask about it at next oil change) and you hear the exhaust note change. Before muffler delete, didn't notice a thing.

 

We'll see. No tunes until out of warranty for this guy.

[hurricanoday]

I am the same way, why would you want to disable this? I have no idea when it is in v4 mode in my denali. I try to get it in there as much as possible and have to use the setting to tell when it is in v4

[oneandzero]

See the point I was trying to make. How can one persons truck work that much different than another's and the dealer saying it's working as gm designed it. The point I tried to make to the dealer at the time was I didn't think it was working right. I drove a buddies truck and his was as yours. Unnoticeable on the transition but was in V8 more than V4. They ran their diagnostics and it was in spec. So I was at a loss.

Man wish I could have gotten one of the perfect GM trucks.

 

 

 

 

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[LongrangeLauber]

See the point I was trying to make. How can one persons truck work that much different than another's and the dealer saying it's working as gm designed it. The point I tried to make to the dealer at the time was I didn't think it was working right. I drove a buddies truck and his was as yours. Unnoticeable on the transition but was in V8 more than V4. They ran their diagnostics and it was in spec. So I was at a loss.

Man wish I could have gotten one of the perfect GM trucks.

 

 

 

 

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It's all dependent on weather conditions, the driver's foot input, how fast you drive, how flat the roads you drive on, gearing in the truck, traffic conditions, everything basically lol

[oneandzero]

It's all dependent on weather conditions, the driver's foot input, how fast you drive, how flat the roads you drive on, gearing in the truck, traffic conditions, everything basically lol

I guess my driving style location and weather set the afm to always on. Lol

Anyways I've said before the tune did wonders for my truck and so far my mileage hasn't suffered.

[Eddie 70]

 

V4 works well on mine. 50/50 interstate back roads to work.

[ThompsonZ71]

Ok to the people getting 24 mpg, what are your commutes like? All highway, mostly highway? Do you have a tune for fuel efficiency? I just got my truck and put 350 (km) on it so far and get nowhere near that. its been about 50/50 highway and city driving and i've been driving very conservatively to try and save gas to get a rough estimate of what it WILL get consistently. I just checked and it was 16mpg ish. Also, how many miles per tank do you all get? Sorry for the noob questions!

[Thomcat]

It's all dependent on weather conditions, the driver's foot input, how fast you drive, how flat the roads you drive on, gearing in the truck, traffic conditions, everything basically lol

Thickness of the seating, the alignment of the planets, what you ate for breakfast and whatever other nonsense they programmed into the operating algorithm. This is my 4th truck with the aluminum 5.3l AFM and none of them worked the same - Avalanches '07 and '12 were seamless in transition except for the change in exhaust pitch, the '12 being much more noticeable - the '13 had a definite sag in acceleration and slight vibration when switching and held V4 way too long in uphill mountain driving which condition worsened with age - the '16 Silverado is seamless, vibration free and I can't even detect the change in exhaust pitch - but. for how long?????

 

I found the V4/8 did get better mileage on a long trip on flat ground doing the speed limit where it remains in V4 mode for an extended period of time. Likely, this is also what helped to turn early ones into oil burners where the deactivated cylinder oil rings would clog and these stuck rings would pass oil to the combustion chamber. Past experience with my Avys noted a number of progressive changes to the system, i.e. baffle for the AFM discharge valve, redesigned valve covers with modified PCV pickup, and a redesign of the collapsible AFM valve lifters, changes being standard on post 1/11 engines which appears to have rectified the oil burning problem. But, at the first sign of this system screwing up in the Silverado I'm plugging my Range Technology device to keep it in V8 mode - used it for the '13 and it worked just fine and unlike an engine tuner, when unplugged from the diagnostic port the engine reverted back to V4/8 without leaving a footprint in the ECU.

[cbit56]

Just another thing to keep in mind when comparing fuel mileage is the time of year and fuel. My mileage was way down during the winter months (winter blend fuel) compared to summer time. V4 works good for flat high way driving. My leveling kit and new tires have also caused a drop in MPG.

[tnchevy]

My mpg's have also gone back up now that it is warmer outside. I only fill up once a month but so far I get about 17 mpg's in the winter and 21 mpg' in the summer. I live in hilly country and rarely on flat terrain so the only time I see V4 mode is when going down hills. I am not really sure how much V4 mode saves me in fuel but I think it is probably not much for the area I drive in. Will probably disable it when the 5 year warranty is up (if I can hold off another 3.5 years!).

[UplandPa]

When I bought my truck I thought the AFM was a negative and was looking at what I could do to disable it and started to do my research. Well some time went by and honestly I don't mind it! It was like I was automatically supposed to hate this thing and get rid of it. Only rarely can I tell when it kicks in. My last 400 mile average was over 23 MPG and I wasn't babying it! At this point I see no reason to deactivate it. My only concern is maybe the longevity of the motor in V4 mode vs. V8, not sure about that!

[phabejhmoob]

Personally, I think the trucks MPG calculator is off regardless of v4/v8 modes. Last fill-up I did with trip A reset i did showed that the truck was getting 19.9 MPG, however when I calculated it manually (miles/gallons), I got 18.6. I saw it as high as 20.4 mixed hwy/city and going to the mt hood and back.

 

I always do manual calculations on all my fill-ups on all my cars.

[hurricanoday]

Personally, I think the trucks MPG calculator is off regardless of v4/v8 modes. Last fill-up I did with trip A reset i did showed that the truck was getting 19.9 MPG, however when I calculated it manually (miles/gallons), I got 18.6. I saw it as high as 20.4 mixed hwy/city and going to the mt hood and back.

 

I always do manual calculations on all my fill-ups on all my cars.

How do you know how much gas you used or left in your tank for the calculations?