Gas Mileage

[Bigburb3500]

I avg 15 mpg locally = 380 miles on 25.5 gal tank
and
18.5 mpg hwy = 470 miles on 25.5 gal tank

This right here. 25.5 x 9mpg = 229 so I feel this is a bit on the low side?

 

[Bigburb3500]

I avg 15 mpg locally = 380 miles on 25.5 gal tank
and
18.5 mpg hwy = 470 miles on 25.5 gal tank

This right here

 

[petethepug]

Our 09 Esky w/ almost 185 orig clicks is finicky. Anywhere from 6-14 mpg on e85. The Trans is new. No AFM on the 6.2L in 09 so that’s part of the issue.

I have a lot of idle time, 100% a/c use, AWD, a heavy footed highway entrance and tons of local hills and stoplight traffic. The 14mpg occurs on 10mi+ highway trips at 65-80mph.

I’ve got new OEM injectiors, o2 sensors, exh mani gaskets, fuel pump & an intake / combustion chamber scrubbed with e85 scrubbing bubbles.

It’s par for the course on your milage. Until you can get a 10SP trans it won’t change. In our area of SoCal Prem is $5+ so the 100 octane e85 @ $2.79 feels 403/417 hp/tq evil good in an AWD 6.2.

 

[Doug118]

^^The exhaust leak can adversely affect the trims. Short trips are also notoriously bad for gas mileage. Have you looked at short- and long-term fuel trims lately? Does it even go into closed loop on the trips to work?

Not on my way to work but this was after driving around the city for a bit

 

[Doubeleive]

My 08 Escalade gets a whopping 6mpg right now. It has an exhaust leak at one manifold but I really don’t think it would make the mileage be THAT bad. Pretty aggravating to have to put $120+ in fuel in it a week when I only work 2 miles from home

BAD CAT'S will make you loose a couple mpg as well, mine was getting down to 8 and threw a cat code, new cat and it went back up to 10

 

[j91z28d1]

you add the short term and long term together. so about 6% extra fuel being added on both sides. which isn't to bad.. under 5 is fine. but also it's at 44% purge, which is I believe is opening the Vapor cansier. they might be adding more fuel too. but I don't know that forsure.

keep an did on the short term and long term trims. if you see say 10% fuel, it's definitely running richer than it should

 

[Fless]

In the first graphic the driver's side is adding over 10% while the passenger side is flat. 10% is getting up there, especially since the banks aren't balanced within reason.

 

[swathdiver]

Adding to the many mileage posts. Full tank just topped off. A whopping 276 miles. I still haven’t gotten the transmission serviced and I’m thinking my likely failing torque converter is contributing. Still, she drinks what she drinks and so far I love her. (Will love her more when I finally pull the trigger on a supercharger. Then I’ll hate her while I shop for a new motor and trans. Then I’ll love her again until I do something else stupid. Like doing the SierraKon conversion. lol.)

What was your average speed for the last tank of gas?

When my average speed is below 21 mph for a tank of gas the mpgs will be about 12-13 mpg. She'll be burning about 1.2 to 1.6 gallons per hour. She burns about 3/4 of a gallon per hour just idling with the AC on. It's even been in the 10s before on gasoline, probably lots of idling and local driving.

Poor quality fuel doesn't burn as efficiently either in these Gen IV engines. Mine gets E85 or top tier 93, never 87.

 

[Joseph Garcia]

I get 10-12 mpg in the city and 14-16 mpg on the highway at 80 mph.
I get 18 mpg on the highway with my wife in the truck with me.

 

[Writefast]

What was your average speed for the last tank of gas?

When my average speed is below 21 mph for a tank of gas the mpgs will be about 12-13 mpg. She'll be burning about 1.2 to 1.6 gallons per hour. She burns about 3/4 of a gallon per hour just idling with the AC on. It's even been in the 10s before on gasoline, probably lots of idling and local driving.

Poor quality fuel doesn't burn as efficiently either in these Gen IV engines. Mine gets E85 or top tier 93, never 87.

Mostly in town and short trips. 20-25 mph average max. I’ve yet to find e85 here (Tallahassee Fl. Probably here somewhere but I haven’t looked specifically for a station that carries it.) And I alternate 93 and 87. Running 93 right now. Just done replacing a lock and a window mech. Which has no bearing on this conversation, just sharing. lol. To be clear I still love this truck, was just lamenting relatively old school v8 problems. lol.