2016 5.3 V8 with 8 Speed loses 1 MPG

[TxTruckMan]

LOL! I'm averaging 17 MPG with my 6.2L over 1500 total miles - 50/50 city/hwy daily commute.

[BeauTie]

 

 

12.7 city and 18 Highway is woefully low compared to what I am getting. I get about 18 in mixed driving 60% stop and go and 40% highway. I have 3.42 gears 5.3L CC.

 

Yeah, looking at the data on Fuelly for the 2015 5.3L, there are 600 fill-ups with an average around 18 MPG or maybe a shade under that. Intellichoice publishes details on their test (http://www.intellichoice.com/real-mpg/how-intellichoice-real-mpg-works.html) but it sounds like their city loop is really a city loop (avg 22 MPH, 22 turns, etc.) and their highway test is 65 MPH with normal driver acceleration and 60% of the highway test is with the A/C set to max. The numbers are obviously more pessimistic than the sticker numbers but they are a little interesting to check as real-world measured reference because the EPA numbers are not routinely achievable in many vehicles.

[tnchevy]

This is the first vehicle I have ever owned that I have never reached the top end of the EPA numbers on a tank of fuel. All of my other vehicles have met it or exceeded it. My 2002 was rated at 14 city 18 hwy and I usually averaged 18 mpg on just about every tank.

[SMiller]

Keep in mind the 8-speed is able to keep the motor in the power and more vs bogging or over revving, also keep in mind that the lube pump on the 8-speed is a dual pump design that keeps the trans from sucking as much power as it only lubes what is needed.

 

The 8-speed WILL get better mileage, can it be trusted or worse yet will it have the dreaded 2-1 clunk has yet to be seen, I am sure with the shit tuning GM puts in these trucks the trans will seem even worse even though it is better.

[bboyce536]

In motor trends TOTY competition, their mpg testing the 8 speed 5.3 came back at 17/24. While the 6.2 8 speed matched the EPA ratings of 15/21.

 

They also raved about how good the 8 speed matched the 5.3 vs. How terrible they felt the old 6 speed was. I know I wouldn't be happy with anything other then the 8 speed in my 6.2.