So Tell Us About Dynamic Fuel Management in Your 2019 T1's

Stex · June 1, 2019

On ‎5‎/‎30‎/‎2019 at 5:10 PM, FDHog said:

I have a 19 AT4 with 6.2L. Was a little leery coming from an F150 to the GM DFM system. So far, I don't even notice it. When I hit the gas, it responds quickly. The Catback doesn't sound any different as far as I can tell. Very happy so far. Hopefully this system has some longevity. If I keep the truck past 3 yrs, I'll go for the extended warranty for peace of mind.

This... Way to early to tell if the DFM will have the early 4-5 yrs problems the AFM had. And then the lifter failures at 100,000 or so. I know there is more hard ware on DFM and they may be using the same AFM lifters? Hope not. And the software for DFM is way more complex. Only miles and time will tell the story on dependability.

Good to know DFM is at least seamless. GM said AFM contributed less than one MPG on the EPA MPG. I have not heard on DFM. Probably around a mile per gallon? IF I end up with DFM, I will disable it to try and save the hard ware/lifter wear and tear.

KARNUT · June 1, 2019

Vindication finally. Back in 2014 when I had my GMC I did quite a few trips on the same freeway. With a tune I tested cylinder deactivation routinely. No change in fuel mileage on or off at 72 mph normal freeway speeds. Let’s add a bunch of breakable parts to gain very little. So what do they do? They add more. My goal in automation, buy a V-8 that can run on 6-4-2 cylinders, not!

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FDHog · June 1, 2019

My Harley had 1 cyl deactivation (when idling), but they let you disable it. Disabled it the first day and left it that way.

As soon as Range comes out with their module, I will be getting one.

NW-99SS · June 3, 2019

I posted another thread about this, but my 2019 5.3L A8 is very noticeable going into DFM modes. The vibration is immediately evident through the seat feel, something my 2017 6.2 has never done (I only ever felt it kick back to V8 from V4 mode, but no vibrations).

I seem to be the minority of users who experience more vibrations in the new 2019s and up, than my past 2014 and current 2017 Denali 6.2s.

Puddintang · December 14, 2019

I have a 2019 5.3L with 8 speed trans 8L90 , I feel it, I hear the rumble and I wear hearing aides, I hate it. Waiting on Range also.

MacLaren · December 15, 2019

2019 LT Z71 and she is seamless.

I have no idea when it changes. Throttle response is awesome. 8 speed tranny is very nice. I love it.

Greyhound · December 22, 2019

On 2/14/2019 at 2:06 PM, Sierra Dan said:

That sounds similar to what I experience with my Sierra. You can feel a slight minor tugging sensation and a very subtle vibration.

I just bought one 2019 Silverado and it vibrates in 8th gear and steady getting worse with only 1200 miles on it.

Tom754 · December 23, 2019

I've had my 2019 Silverado about 8 months now. It's been great. For the last couple of months, I've been trying to track down the source of a low rumble and vibration. Thought it might be the tires or drive train. Had it checked out, but all good. It makes it at speeds of 20 to 40 when I'm on a flat road and applying very slight throttle. I now think it is one of my cylinders not firing properly and is only noticeable when many of the others are deactivated. Thoughts? One other thing. I can make it stop if I shift to low and manually control my transmission. I believe my DFM is off then.

Edited December 23, 2019 by Tom754
Add more info.

Minnvmax · December 23, 2019

Pretty seemless for me too. Does not trip my irritable alarm one single bit. 6.2 10-speed

Edited December 23, 2019 by Minnvmax

Greyhound · December 24, 2019

On 12/22/2019 at 7:17 PM, Tom754 said:

I've had my 2019 Silverado about 8 months now. It's been great. For the last couple of months, I've been trying to track down the source of a low rumble and vibration. Thought it might be the tires or drive train. Had it checked out, but all good. It makes it at speeds of 20 to 40 when I'm on a flat road and applying very slight throttle. I now think it is one of my cylinders not firing properly and is only noticeable when many of the others are deactivated. Thoughts? One other thing. I can make it stop if I shift to low and manually control my transmission. I believe my DFM is off then.

Mine vibrates between 64 and 68 with cruise control set on flat ground and also between 20 and 30. Going to Chevy dealer Thursday for 3rd time with only 1500 miles on it. They will fix it or I’ll trade it . Mine also does good manually shifting.

Tom754 · December 24, 2019

I'll get my truck back into the dealership and let you know what I find out.

SquireSCA · December 24, 2019

DFM is a crappy solution to a problem that doesn't need to exist. All this complication and additional points of failure, and for what? 1mpg?

What's that equate to when you fill your tank? $1.97 per tank? It's chump change. Nobody is spending $50k on a truck and worrying about $2 when they fill up. If they do, then they are either stupid, or bought a truck well beyond their budgetary means.

Hoping that Range delivers soon, because while it's more transparent than AFM, I do hear and feel it, and I don't want lifter issues if I decide to keep the truck long term and if there is no tangible benefit to me, which 1MPG or so says that it isn't, then I don't want it and want to disable it like I did on my 2018...

MacLaren · December 25, 2019

I'm getting 22.5 mpg from 17.5 mpg on my 07 classic. That's a 5 mile per gallon difference.

SquireSCA · December 25, 2019

12 minutes ago, MacLaren said:

I'm getting 22.5 mpg from 17.5 mpg on my 07 classic. That's a 5 mile per gallon difference.

So, the new one has the same weight, transmission, tires and aero package and number of miles on the motor as the 2007 Classic?

Hard to conclude that the DFM is the sole factor for the difference in mileage...

MacLaren · December 25, 2019

1 hour ago, SquireSCA said:

So, the new one has the same weight, transmission, tires and aero package and number of miles on the motor as the 2007 Classic?

Hard to conclude that the DFM is the sole factor for the difference in mileage...

Not really. 5 mpg is a huge difference.

Heck, 17.5 was damn good mpg to begin with!

I'm very happy.....

edit* and, that's just around town. I would expect 24-25 mpg on a trip. That's just incredible.

throw in the fact that it's not only seamless, but much quicker off the line and faster and bigger than any other Silverado.

GM killed it imo.

Edited December 25, 2019 by MacLaren