2024 LTZ mileage vs previous 2017

rrmccabe · July 22

I traded in my 2017 High Country (4wd) for a 2024 LTZ. Both are 5.3 liter and very similar trucks although the 2017 had a slightly longer bed.

I have read that the trucks are still AFM or DFM even though the instrument cluster does now show it. I could not find anything in manual and my Window Sticker does not indicate that either.

I do a lot of driving on my area which is not exactly city but not hwy either. Mostly 25 to 45 mph speeds. The High Country would easily stay in the 19.x mpg range and I even got 27.x out of it once on the highway although 24mpg was more common.

The new truck under the same conditions is doing about 15.x mpg. Trying to take it easy, watch the mpg meter and it just is really not busting into the 16s yet let alone 19s. I would assume break in might help, but I would have guessed going from a 17 5.3L to a 24 5.3L would have not cost me any mileage. Not to mention the 2024 is a little smaller truck.

Anyone have similar experience?

Picture below was on the way to the dealer to be traded in and represents typical.

In all fairness it has got some excessive idle time figuring stuff out and maybe it averages over a greater distance and I need to be more patient

Edited July 22 by rrmccabe
5.4 TO 5.3

newdude · July 22

1 hour ago, rrmccabe said:

I traded in my 2017 High Country (4wd) for a 2024 LTZ. Both are 5.4 liter and very similar trucks although the 2017 had a slightly longer bed.

I have read that the trucks are still AFM or DFM even though the instrument cluster does now show it. I could not find anything in manual and my Window Sticker does not indicate that either.

I do a lot of driving on my area which is not exactly city but not hwy either. Mostly 25 to 45 mph speeds. The High Country would easily stay in the 19.x mpg range and I even got 27.x out of it once on the highway although 24mpg was more common.

The new truck under the same conditions is doing about 15.x mpg. Trying to take it easy, watch the mpg meter and it just is really not busting into the 16s yet let alone 19s. I would assume break in might help, but I would have guessed going from a 17 5.3L to a 24 5.3L would have not cost me any mileage. Not to mention the 2024 is a little smaller truck.

Anyone have similar experience?

Picture below was on the way to the dealer to be traded in and represents typical.

In all fairness it has got some excessive idle time figuring stuff out and maybe it averages over a greater distance and I need to be more patient

If you have low miles on your new one, say under 3000-5000mi, you might see worse MPG initially as its not really "broken in" yet. The idle time doesn't help either of course.

As much as your bed is shorter though, these new trucks are larger than the old ones. Wider and taller, and much taller frontal area. They are lighter though than the old trucks, about 200-400lbs depending on configuration (like truck so say crew cab short box 4x4 from each generation).

Your new truck is DFM. Dynamic Fuel Management. All 8 cylinders are equipped with the deactivation lifters. The algorithm has 17 different modes of operation for how many cylinders its using/deactivating.

Also, 5.3 not 5.4

Edited July 22 by newdude

rrmccabe · July 22

Thanks for the reply. Yea 5.4 was a typo

I need to check manual to see if there is any info on the mpg screen to see if it averages over a longer distance. The last truck I could work at it and see quicker improvement. I think it averaged over the last 25 miles.

My admitted excess idle time would make it harder to bring that mpg up if the sample distance was longer.

I just was not expecting any change in engine from 2017 to 2024 and would like to get back to that 19.x range. I think I am past the excess idle time now so maybe I will just reset it and see how it does.

And yes, I am way under the 3000 to 5000 mile number you referenced. Actually about 500 miles. But just finished my second tank of fuel and topped off yesterday.

redwngr · July 22

DFM engines can run in something like 17 different 'modes' --- so there is no spot on the dash that indicates which mode it is in.

If you put up the mpg page that shows best, instantaneous, and the rolling 'current' average --- and set it to show the 25 mile setting --- it can give a good idea of what is is doing under current driving conditions.

The mpg screen can be set to show rolling 25, 50 or 400 mile averages.

Tripmeters will show miles driven and average mpg since the last time they were reset.

If you reset one of the tripmeters at each refill it it can easily be compared with handcalc tank averages.

The truck does the mpg calcs for 25/50/400 all the time but only displays the one selected -- but you can switch between them at any time, without losing any accumulated data.

All 2024 1500 LTZ with 5.3 have the L84, which is the DFM version

rrmccabe · July 22

Thanks, guess I missed that the distance averages could be set. Changing it to 25 will certainly help me see the mileage improve as I drive it 'nicely'.

Rich

CamGTP · July 23

They can get good fuel mileage on the open road that's for sure. My parents just got back from the black hills in their 2021 Silverado 5.3 and they avg'd around 22-24mpg for the whole trip. So many 50 mile stretches of 27-28mpg with the right roads, winds and traffic.

rrmccabe · July 29

Dropping the setting to average over 25 miles definitely helped me see changes quicker and see improvements when I attempted to drive in a manner to get decent MPG.

I am not terribly behind the 2017 at this point and hope the 2024 continues to improve.

I would like to like to get that auto start disable as I never remember to shut it off. I think in my situation that is hurting mileage and not helping because the truck is never off more than 5 seconds.

repairman54 · July 31

My Chevy has the mileage 25 to 450 average gauge and a drive cycle one. The drive view resets itself on every ignition cycle. My '23 6.2 averages 19-20 mpg at 60 mph. 23k miles on it now.

redwngr · July 31

24 minutes ago, repairman54 said:

My Chevy has the mileage 25 to 450 average gauge and a drive cycle one. The drive view resets itself on every ignition cycle. My '23 6.2 averages 19-20 mpg at 60 mph. 23k miles on it now.

It should also have tripmeters (A and B) which can be manually reset.

They might be turned off in the display options settings -- but they are calculating anyway.

They are useful for comparing the trucks calcs with the hand calcs when refuelling.

I turn off one tripmeter so it doesn't accidentally get reset and use the second for mpg comparison.

Previous trucks I'd never reset the 2nd tripmeter.

I'm disappointed that with this generation the tripmeters will only display 4 digits, so the they roll over after reaching 9999

2016 Sierra Owner · August 1

On 7/22/2024 at 2:24 PM, rrmccabe said:

I traded in my 2017 High Country (4wd) for a 2024 LTZ. Both are 5.3 liter and very similar trucks although the 2017 had a slightly longer bed.

I have read that the trucks are still AFM or DFM even though the instrument cluster does now show it. I could not find anything in manual and my Window Sticker does not indicate that either.

I do a lot of driving on my area which is not exactly city but not hwy either. Mostly 25 to 45 mph speeds. The High Country would easily stay in the 19.x mpg range and I even got 27.x out of it once on the highway although 24mpg was more common.

The new truck under the same conditions is doing about 15.x mpg. Trying to take it easy, watch the mpg meter and it just is really not busting into the 16s yet let alone 19s. I would assume break in might help, but I would have guessed going from a 17 5.3L to a 24 5.3L would have not cost me any mileage. Not to mention the 2024 is a little smaller truck.

Anyone have similar experience?

Picture below was on the way to the dealer to be traded in and represents typical.

In all fairness it has got some excessive idle time figuring stuff out and maybe it averages over a greater distance and I need to be more patient

Yes I went from a 15 6 speed to a 20 10 speed. Same roads same driving habits. My MPG actually stayed the same. Now that I have a 24 the MPG is even less I've barley gotten into the 16 MPG range. This is all relying on the trucks readout and no hand calculation though.