New 21 Silverado with 5.3 and NO DFM

[Spanky06]

Hello all,

    I am new to this forum, but I have been a lifelong Chevy man. I recently traded my 2015 Silverado LT Z-71 for a 2021 Silverado LTZ and I went with the 5.3 as it has been great for me since my first Silverado in 2003. My new truck did not have the DFM due to the chip shortage, the dealer took 50.00 off the sticker because of that (SMH). My question is this, could I have DFM installed once the chip shortage gets squared away, this is assuming that there is an open chip slot in the present computer of the truck?. I had AFM in the 2015 and that worked like a champ my 2015. My gas mileage was great. 23 on the highway and 18 in town. All bets were off when I was towing my Bass Boat. Thanks in advance for any information and I absolutely LOVE my new truck

[OGreatOne]

according to this, probably not

 

Here's How GM Will Produce Engines Without Fuel Saving Features Due To Chip Shortage - GM-Trucks.com

 

[Spanky06]

Thank You

 

Spanky

[Ken M.]

I bought the same truck and same sticker no DFM. Unless I'm mistaken I'm happy without it. It seems to cause issues even engine failure.

[Spanky06]

Yes, I am liking mine as well, Great Truck as always, this is my 4th Silverado

[GarandPappy]

My 2021 Z71 RST didn't come with it either.  All that tech involved and they took off a whoppin $50.  As I have looked at MPGs on different stickers, I haven't noticed more than 1-2 MPG difference.  I've actually averaged between 16-17 and that has been all in town for just under 600 miles.  I was actually glad it didn't come with it.  We have a 2011 Tahoe LTZ and I thought that was the most techie truck I'd ever been in.  I do have the AutoStop, and I cannot say that I am a fan of all that.  I think I might like it for more highway driving, but not the stop and go I'm in so much.  

• 2021 with NO DFM
  • 
• 2021 with DFM
  • 

[OGreatOne]

It's interesting to look at those MPG's. I would think that the DFM would have a greater benefit at highway speeds but it looks like it has more effect in city driving.

[Spanky06]

As for the Auto Stop, you can disable it when you start the truck to drive it (At least on mine you can), you are correct GarandPappy, it is a PITA. I am averaging about 17 mpg btw.

 

Spanky

[redwngr]

https://gmauthority.com/blog/2021/06/2021-chevy-silverado-1500-fuel-economy-numbers-without-automatic-stop-start/

[Adamace1]

I'm curious how much of a difference it makes. 2mpg sounds about right. I use my truck 5.3 4x4 crew cab at work, some days I idle a few hours. I'm currently getting over 20 mpg over 12,000 miles. On trips I can get 22 to over 24.

 

With a base single cab 2wd ford v6 my average was never over 20. So I think something chevy does really helps with mpg. I also don't like the auto stop/start and turn it off.