1500 MPG highway

[mookdoc6]

On 7/17/2019 at 6:47 PM, NomadicCPO said:

5.3 CC, 8-speed with 3.42 gears.  Around town in winter ~16mpg, summer ~18mpg.  Highway at 70 ~21-23.  Best ever over a tank was 25mpg...and yes it was on country backroads doing 55mph.

Exact same combo for engine/trans I get exactly same results!  I have 90K and lifetime is 19.5mppg's

[Ravenkeeper]

I religiously drive via my cruise control, set it every time that I'm doing at least 24MPH, and use it to speed up & slow down for speed zone changes.  I very rarely (next to never) go over 65.  Trip B 0n my truck says that I've gotten 18.8 MPGs since I bought it.  Fuelly says otherwise, see signature block, it will be updated later tonight on my way home.  My only dislike with Fuelly is having to estimate how much city vs highway driving I've done, that should automatically show in my AVG. Was running on 87, until May, but have since moved up to 91, and have seen a small increase.

[mikeyk101]

One thing that I didnt see mentioned when discussing mpg was how many are using 10% ethanol gas and how many are using pure gas. That too will make a difference on results.

 

[videoarizona]

2015 Denali 6.2, 8speed, 20inch tires and 3.42. Lifted 2.5"

Average over 7K miles is 18.9. That's what I've put on the truck since I purchased her in March.

That includes city, highway normal driving and towing 4200lb sailboat and/or 6500lb travel trailer part of the time.

She gets about 3mpg's more than my older Yukon XL SLT with 5.3 and max tow.

I'm happy.

[2018GMC]

29 minutes ago, videoarizona said:

2015 Denali 6.2, 8speed, 20inch tires and 3.42. Lifted 2.5"

Average over 7K miles is 18.9. That's what I've put on the truck since I purchased her in March.

That includes city, highway normal driving and towing 4200lb sailboat and/or 6500lb travel trailer part of the time.

She gets about 3mpg's more than my older Yukon XL SLT with 5.3 and max tow.

I'm happy.

Nice setup! What’s your towing mpg?

[Grumpy Bear]

On ‎7‎/‎17‎/‎2019 at 8:36 PM, Flinthills said:

It is fun when the instant readings say I get 13 going up a small hill and 75 going back down. Then the numbers are just a form of entertainment

Can be a tool as well. Coupled with an altimeter and my weather app and speedometer I've found my peak efficiency numbers for various speeds. Do that enough times and  you can make minor adjustments in driving that make large impacts in efficiency. In my area there are many ways to the same place and each one the truck responds to differently. Traffic patterns set by time of day and the list goes on. WAZE for other. Then once you've trained the brain and right foot....it becomes entertainment. Entertainment that pays you to play. 

[videoarizona]

12 hours ago, 2018GMC said:

Nice setup! What’s your towing mpg?

8 to 10 mpg's at 65mph towing the trailer. 10-12mpg's towing the boat. Boat has far less windage as it sits low on the trailer.

[Ezekiel2517]

Since I added the Diablo canned 87 tune I am not getting 20-23 consistently on the highway doing 70mph.  Before it was 18-20.  I highly recommend that tune.  It shift so much better.   Also have an AEM direct flow tube on my air intake.

[jay webb]

i have a 2018 sierra 1500 crew cab with the 5.3

 

i have 9300ish miles on it right now and since i bought the truck new, i have never reset the trip b 

 

according to that i have average 19 miles per gallon since i bought the truck. 

 

my drive to work is 15 miles 1 way. 

 

the best i got over a 25 mile according to the truck was 28.5 mpg 

[16LT4]

Currently about to leave the OBX and go back to NY... on the way down, computer said 16.7 mpg by the time I filled up in DE.  That was on E85 (my worst ever on E85), and I filled up with a quarter tank left with 87 (my first time putting 87 in the truck!).  Since then, the computer was showed 22.4 until I got to the Banks (cruising at 62 mph, occasional traffic light).  Once here, there's been only 45 mph and under speeds, lots of traffic, lights, and even about 10 miles on the beach in 4-hi and 4-lo, and the computer is showing 18.3.  I didn't hand calculate these, as the computer has shown to be within .5 mpg of my hand calculations every time.  The truck isn't heavily packed, but the tonneau cover is rolled up with a couple of bikes laying sideways on top of my gear in the bed, so that does disrupt the airflow.  The truck is all stock right down to it 17" factory wheels (which I hate).

[BEST]

Over the past few weeks I have made changes to my driving habits that have added about 2-3 GPM.  I started to use the time to determine red/green light time periods since I run the same 15 mile path that has about 20 lights.  Learning when to lay off the accelerator and when I need to bump it up to get through a light has reduced my idle at a stop time.  I have toned down my speeds that I used to hustle in the left lane and now do the limit in the right lane.  

Before I was getting about 17 GPM and now I'm around 20.  Better mileage less stress, safer driving and I often catch up to folks that passed me when I get to the next stop.