2021 Sierra 1500 Crew Cab 6.2L w/10spd trans fuel economy

AwwWhatThe · June 10, 2021

What are you all experiencing for MPG/fuel range in your rides? Brand new here (30 miles) and Im getting 5 mpg and a range of 220 max. Im sure it will get better but just looking at whats out there.

Im coming from a 2015 Sierra 1500 w/ 5.3L 8spd trans and I would get roughly 14 mpg city and 20-23 highway with a range of over 450

Whiskeyranch · June 10, 2021

21’ LT TB 6.2 10 speed and I’m getting average 17-18 and at best 23mpg. I drive mostly country roads and rarely sit in traffic. 5 mpg sounds like you’re gunning it often? When I fill up it says 400 miles to empty and I get pretty close when I fill up.

Edited June 10, 2021 by Whiskeyranch
Add info

GullLakeMi · June 10, 2021

I'm averaging 16 mpg on mixed highway/city driving on a '21 Sierra AT4 with 6.2 10 speed after 1,300 miles. This is calculated at the pump. Truck computer reads slightly higher.

With the 24 gallon tank, I'm not getting anywhere near 400 miles before the gas warning light comes on. That is my only complaint - needs a bigger tank. Anybody have a mod for that??

Z45 · June 10, 2021

I just went and looked at mine , 2021 Sierra Denali Crew 6.2L/10-sp. Average 21.4, best 29.7. 5,720 miles. I drive the speed limits, don't hot-rod and mostly semi-rural 2-lane blacktop around here, no freeways etc. If you are getting bad mileage its more then likely your driving style.

Note - I always turn off start/stop, hate that feature and believe is got to hurt the engine (bent pushrods?) over the long run as mine often jerks hard (IMO) when it comes back on.

Edited June 10, 2021 by elcamino

steelcity · June 10, 2021

20 minutes ago, elcamino said:

I just went and looked at mine , 2021 Sierra Denali Crew 6.2L/10-sp. Average 21.4, best 29.7.

LOL, yea right!

taze · June 10, 2021

6.2/10spd RST z71. I picked it up with 3mi on the clock now at 114 mi and it has yet to see a freeway. Lots of stop & go and a decent amount of idling playing with things. I'm not sure the overall average but I'lll look. I can tell you my best 25 mi average is 17.4 and regularly around 15. I haven't taken it over 55 and am driving slower than my grandma adhering to the break in. I am 100% sure it'll get noticeably better when I can really drive it.

SporkLover · June 10, 2021

It gets better over time as he computer is able to store more information about average fuel economy. Initially my range computer said range was low like 220 on a fill.... now It's 350..... but it stays at 350 for a while. I made a 40 mile drive home last week with it saying 350 range. I wouldn't be surprised if that number bumps up for me to something closer to 400 for range.

CXXX · June 10, 2021

2021 SIERRA SLT 6.2 10spd WITH DFM 18.1 mpg so far...only 900 miles on it though.

Edited June 10, 2021 by CXXX

OnTheReel · June 10, 2021

I’ve tried very hard and I cannot get 5 MPG no matter what.

Lifetime is around 13.

EricTheRed · June 13, 2021

On 6/10/2021 at 4:04 PM, OnTheReel said:

I’ve tried very hard and I cannot get 5 MPG no matter what.

Lifetime is around 13.

Try driving uphill both ways into a strong headwind haha

June 14, 2021

Attached are my numbers currently. I have a ton of HWY miles, but also a ton of idling during the day. So I would say it evens out to about 50/50% equivalent HWY/City

blckblt · June 15, 2021

On 6/10/2021 at 1:35 PM, AwwWhatThe said:

What are you all experiencing for MPG/fuel range in your rides? Brand new here (30 miles) and Im getting 5 mpg and a range of 220 max. Im sure it will get better but just looking at whats out there.

Im coming from a 2015 Sierra 1500 w/ 5.3L 8spd trans and I would get roughly 14 mpg city and 20-23 highway with a range of over 450

Did you reset the computer (trip and 25/50/400 mile)? Trucks get a lot of idle time before they are purchased.

Grumpy Bear · June 15, 2021

On 6/10/2021 at 1:57 PM, GullLakeMi said:

I'm averaging 16 mpg on mixed highway/city driving on a '21 Sierra AT4 with 6.2 10 speed after 1,300 miles. This is calculated at the pump. Truck computer reads slightly higher.

With the 24 gallon tank, I'm not getting anywhere near 400 miles before the gas warning light comes on. That is my only complaint - needs a bigger tank. Anybody have a mod for that??

Yes! A 4.3 and a six speed!

:rollin:

Kidding aside; books are written on this topic and I think I could add a few paragraphs to most of them. Trip length...

It's hard to imagine how much impact trip length has on fuel economy. If you could find a really flat piece of road after the truck is fully warmed up, driving over an hour interstate highway, on a windless day and drive that around 48-53 mph observing your 'instant' meter you will know approximately what your truck is capable of. Now...how much of that you get to keep is up to your choices and your circumstances. We can't control everything.

In that first hour of driving most of what you don't get to keep is used to bring fluids to heat reducing viscous drag. The colder the day the longer this takes. You start the day at zero mpg and for an hour it improves until it becomes the best it can be. That period of time will have an average. That average is a fraction of your trucks capability. That number you tested for earlier. Drive long enough and that average will get really close to your best. This could take a hundred miles or more.

Once up to heat that period of time used in building it's 'average' gets shorter and shorter. You've seen this on trips requiring more than one tank of fuel. Second tank is almost always better than the first and the third marginally better than the second.

Hint: NHRA Pro Stock class racers use 0W or 5W racing oil. Their trip length is a quarter of a mile and the oil temperature at the end of the quarter might not reach 100F. 5 weight oil it more viscous at 104 F than 60W is at 212 F.

Next two biggest users of fuel are a Micky D's drive through and taking the wife anywhere.

:crackup:

kodiakdenali · June 16, 2021

Don't have the exact numbers but I'm getting low-mid 20's (mostly low) I can easily get over 20 on the highway which is a very nice update from my last truck which gave me 12-14 even on the interstate. 2020 Sierra Denali crew cab, standard bed, 6.2L 10 speed, Whipple supercharged. auto stop-start disabled and after doing my exhaust video (on my youtube channel) and really paying attention to the sound and the throttle response, I pretty much drive in L mode at all times now = no DFM, and I only shift it up to L10 to allow DFM to operate when I'm cruising on the interstate.

full size pickup, huge engine, largest body configuration, a handful short of 600bhp, and 22-24mpg on the highway....life is good in my garage.

Amcguy1970 · June 16, 2021

On 6/10/2021 at 2:50 PM, elcamino said:

Note - I always turn off start/stop, hate that feature and believe is got to hurt the engine (bent pushrods?) over the long run as mine often jerks hard (IMO) when it comes back on.

:wtf: Should let the engineers, designers and testers know you found something they missed in the hundreds of thousands of hours of design and millions of miles of testing...

So no facts, no back up or experience just an assumption of yeah you have a feeling this is going to horribly damage a key internal part of the engine you have no experience with and instead choose to spread fears to others :rolleyes: