MPG curiosity.

Jonathan Floyd · February 7, 2020

just out of curiosity for the MPG. I have a 2019 custom trail boss with the 5.3 6 speed and I maybe get low 16’s for city and 19-20 mpg on the highway. Even though it’s lifted with 32 inch durratracs I thought silverados got pretty good mpg. I’m coming from a ram I just curious how I’m getting about the same mpg from a hemi but my 5.3 has less HP and torque so I was thinking it would get better over time. So my question is why does the 5.3 get about the same mpg has other V8’s even though it has less HP and TQ?

Edited February 7, 2020 by Jonathan Floyd

BlancoSilverado · February 7, 2020

FYI, larger/ heavier tires will hurt MPG(more in the city). lifted vehicles will be worst also.

The TB doesn't have active shutter to help with aero.

the custom TB (5.3 with 6 speed) has AFM and not DFM. AFM will only make the vehicle a 4 cylinder, DFM can go down to 1 cylinder.

How fast are you going on the Hwy? speed will kill MPG also. the wind force grows exponentially as speed increases.

I believe that 19-20 on the HWY is pretty good, for the motor the trans and the lift.

Im getting 20-22mpg doing 70mpg. mine is a stock 5.3 8 speed (LT model)

wizard4878 · February 8, 2020

was your ram 4X4? I only ask because the only other person that I ever heard say they got more than 16mpg from a Hemi had a 2X4, and he only gets about 18 on its best day

scotman623 · February 8, 2020

My 2020 TB with just over 4500 miles is averaging 15.8 mpg since I picked it up... This includes all types of driving with the crap winter blend fuel.. I’m hoping to see 1.5-2.5 mpg more with summer fuel, I have in any other truck or vehicle I have owned....

romclean1 · February 9, 2020

I’m getting 16.2 combined city and highway. Long trips I can get 19-20 if I take it easy, 17-18 if I’m driving with a bit more urgency.

MacLaren · February 20, 2020

Just let em get broken in guys.

2019 Crew Cab 4x4 Z71

I can easily get 21-22 mpg and whenever I want, 25 mpg as well

I live in the heart of the Appalachian mountains, so no long straight a ways, up down and curvy

At anyrate, here is my last tank on 89

Could've prolly squeezed out 600 miles!

JD19 · February 22, 2020

You guys should be happy. I have a 19 base Sierra with the 4.3 V6. It has been getting 14 mpg in the city. No matter what I do, I can't seem to improve the number. I firmly believe that the massive hood on the Sierra/Silverado along with its bulky shape is creating excessive wind resistance thus leading to less than expected mpg.

Edited February 22, 2020 by JD19

Ryno12 · February 22, 2020

You guys should be happy. I have a 19 base Sierra with the 4.3 V6. It has been getting 14 mpg in the city. No matter what I do, I can't seem to improve the number. I firmly believe that the massive hood on the Sierra/Silverado along with its bulky shape is creating excessive wind resistance thus leading to less than expected mpg.

As I mentioned in the other thread you posted the same comment in, small motors don’t necessarily equate to good gas mileage. That little engine has to work a lot harder to get that truck moving than the larger V8’s. I would think certainly a 5.3, & quite possibly even the 6.2, would get better gas mileage than your 4.3.

AlaskaTB · February 22, 2020

I have a 2020 Custom Trail Boss, 5.3 and 6 speed and 3.42 rear with 2200 miles. Changed tires to firestone winter force studded. Living in Alaska and I have a newborn so I am warming the truck up with remote start every time. Usually about 10 min of idle before I drive off.

I am about 50/50 city and hwy driving. My milage is 17.5 mpg for the 2,000 miles I have on this truck. I don't drive faster than 65 and most of the time its at 60 mph. On flat road at 60 mph I can get 23-24 mpg easily. Most of my highway driving with a few hills mixed in comes to 21 mpg average.

This is hand calculated, when compared to the truck info screen my millage is always within 3%. I have been very impressed how accurate the screen says my millage is.

I expect to see a loss in milage when I put back on the duratrack tires. They weigh 7 more pounds per tire and have a much more aggressive tread.

So far I have been very pleased with the millage.

JD19 · February 23, 2020

22 hours ago, Ryno12 said:

As I mentioned in the other thread you posted the same comment in, small motors don’t necessarily equate to good gas mileage. That little engine has to work a lot harder to get that truck moving than the larger V8’s. I would think certainly a 5.3, & quite possibly even the 6.2, would get better gas mileage than your 4.3.

You are correct. However, the 4.3 in the 2014-2018 model years (exactly the same set up as in 2019) was achieving much better mpg than in the 2019 model even though the 19 is lighter in weight. In addition, I had the 5.3 V8 on my old 2010 and it was getting the same mpg as the 4.3 on my 19. It also appears the 4.3 AFM system does not keep the motor in 4 cylinder mode as long as the system in the 5.3. Nonetheless, I believe it's the big hood and bulkiness of the truck that is the primary culprit. The F150 and Rams are less bulkier and have more aerodynamic hoods. They seem to be getting better mpg than the Silverado/Sierra twins.

outcastdon · February 24, 2020

I have a 2020 Z71 crew cab. 6.2L, 10 speed. Currently averaging 17.2 mpg overall. Can manage 21 mpg at 70 or a little more. Better highway mileage than my 17 with the 5.3.

BackWoodsLivn · February 25, 2020

Primarily rural driving for me. Secondary roads with some stop signs, no stoplights/city, and the best I have achieved is 20.7 mpg and that was feathering the throttle and really trying to maximize the fuel. To me, this seems right in line with the estimated mpg of 18/22.

Sjordan · February 26, 2020

Pretty mixed driving in a 2019 custom TB with about 13k miles. Lifetime average is about 18mpg. I probably could do better if I slowed down on the highway, but I usually am around 75-80 mph.

PATrailBoss19 · March 4, 2020

Man I am on the low side with my 19 LT TrailBoss. The 5.3 and the 8 speed I am can barely break 15mpg all around average. I have 8k miles and a swapped the stock muffler for a Borla XR-1 muffler. Hopefully it gets better after this winter blend gas is gone. Has any been using the 88 octane 15% ethanol gas? A friend is using it in his 2020 RAM and say decent improvements.

Duramax3oh · March 4, 2020

As mentioned previously, the tires will make a significant dent in the mpg you see.

Tread: Highway tread > All Terrain > Mud Tires

Diameter: 32 > 33 > 35"

Width: 10 > 11 > 12.5"

Add it all together you also get Weight: 40 > 50 > 60lbs

Was excited about a previous Ford F150 Ecoboost untill I put on bigger more aggressive tires. Loving my 3.0L Duramax now but know I'll soon take a hit when tires get "upgraded". Can't do an Apples to Apples comparison with your Hemi unless you changed those tires and got a lift too.

Edited March 4, 2020 by Duramax3oh