2016 5.3 V8 with 8 Speed loses 1 MPG

[Dunc]

The 8 speed is too busy searching for the right gear to worry about gas mileage.

[jamin87ss]

The new aero grill and hood gaps lmao

[Greystoke]

"While the public mistakenly presumes that this federal agency is hard at work conducting complicated tests on every new model of truck, van, car, and SUV, in reality, just 18 of the EPA’s 17,000 employees work in the automobile-testing department in Ann Arbor, Michigan, examining 200 to 250 vehicles a year, or roughly 15 percent of new models. As to that other 85 percent, the EPA takes automakers at their word—without any testing—accepting submitted results as accurate."

 

http://www.caranddriver.com/features/the-truth-about-epa-city-highway-mpg-estimates

[redwngr]

The 8 speed is too busy searching for the right gear to worry about gas mileage.

Mine doesn't seem to need to hunt to find the right gear.

[Greystoke]

GM's official reasoning for the MPG loss:

 

"the eight-speed is currently offered only on the higher trim level trucks, those trucks have heavier weights than the more basic models equipped with the 5.3L V-8 and six-speed transmission."

 

http://www.trucktrend.com/news/1510-2016-chevy-silverado-5-3l-with-eight-speed-gets-1-mpg-less-than-six-sp/

[tnchevy]

Makes you wonder then why they don't release the mpg's for every cab, bed, and engine configuration as well as by trim. Sounds like BS to me.

[WendysOrBust]

Makes you wonder then why they don't release the mpg's for every cab, bed, and engine configuration as well as by trim. Sounds like BS to me.

 

Because unlike payload numbers which can be easily calculated, mpg numbers have too many variables. Fuel quality, elevation, driving habits, average speed, wind, can all greatly affect mpg numbers both ways. However, I do agree that manufacturers need to be more upfront on the exact truck configuration used to achieve their advertised mpg numbers.

[ptheman]

Mine doesn't seem to need to hunt to find the right gear.

neither does mine

[ptheman]

neither does mine

please let me add that I also have the 3.23 in my 6.2 litre 8-speed like redwngr ... so our powertrains are identical with, based on redwngr's post, no complaint from him on shifting as well as myself

[ptheman]

please let me add that I also have the 3.23 in my 6.2 litre 8-speed like redwngr ... so our powertrains are identical with, based on redwngr's post, no complaint from him on shifting as well as myself

sorry ... I should also let you know that my truck was manufactured in June of 2015 ... maybe this provides some relevant information as to the software version that would have been applicable to the June production month.

[SULLVERADO]

I think it's because the 8 speed is only available in the upper trims, and those come standard with the 3.42 gears. I don't think you can get the 3.08 in LTZ or SLT for 2015, can you?

 

 

my 2014 LTZ Z71 has 3.08

my dads 2015 LT Z71 has 3.42

both are 18" wheels

[Tattooo]

The 8 speed is too busy searching for the right gear to worry about gas mileage.

Sounds about right

[2004lebanshee]

pass. Would drive me nuts towing. Shift shift shift shift shift shift.....

[redwngr]

pass. Would drive me nuts towing. Shift shift shift shift shift shift.....

My experience is that it does not hunt when towing.

 

When it needs to downshift it does so seamlessly, without 'racing' the engine. When speed and grade requires it will downshift and stay downshifted without a fuss. I've done interstate hwy runs where it ran for miles in 5th or 6th, and lots of times where it ran long periods in 7th.

 

For sure it shifts less on the highway than older transmissions did.

 

If only they could make the annoying 2-1 clunk disappear. It is less harsh and much less frequent with the latest update, but still occurs occasionally.

[Badass69]

Maybe with the 5.3 in front of the 8L90E it will hunt.... hard to say. I honestly doubt it though. I drive the worst 6.2 combo being 8 speed and 3.23 ( but in a lighter package being a double cab LTZ) and it tows 9000 lbs on hilly ground without "hunting" so it's an unfounded complaint. Mine is a February build but had a couple TSB's completed and shifts just fine even for stock.

 

The worst shifting stock trucks I have ever driven were all 6 speeds so I don't think you can get any worse than those. This 8L90E is not perfect but it's not as bad as any of the past 6L80E and 6L90E equipped trucks I have been stuck with.