FUEL MILEAGE

DISAPPOINTEDOWNER

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NEW TO THIS SITE:
NEW OWNER OF A 2023 ZR2 LOVE THE TRUCK BUT THIS FUEL MILAGE IS REDICULOUS!
I HAVE HAD A 2014 GMC AT4 (6.2) SINCE NEW , NOW HAS 82000 MILES HIGHWAY 20-21
CITY 15-16 RUNS GREAT ALL AROUND GREAT TRUCK 0 MODIFICATIONS...
NEW ZR2 13 CITY 14.1 HIGHWAY 3000 MILES STOCK
ADDED A 50 SERIES FLOW MASTER NO CHANGE : ( SOUNDS GREAT POWER IS AWESOME)
WHAT HAVE YA'LL DONE TO IMPROVE FUEL ECONOMY?
 
I've got about 9500 miles on mine. About 50% highway and 50% city and dirt roads. My average is 12 mpg. I've seen sustained mileage of 22 mpg in flatter roads with no wind. I've seen 10-11 mpg in town in traffic. It's fairly easy to get 18 mpg on the highway at 70- 75 mph. Wind, hills, and start/stop traffic will kill the mileage. Also, if you do a lot of short trips say 10 miles or less, the average will always be low. Seems like the computer doesn't like to get the average up until about 15-20 miles.
 
That does seem low , I had a 20 Trail Boss with a 6.2 averaged around 17-18 mixed driving conditions
YES SIR ... SAME HWY TO WORK SAME SPEED RUNNING THE CRUSE CONTROL SIMULAR WEATHER CONDITIONS
MY WORK TRUCK 5.3 L 2019 TRAIL BOSS GETS 18.3 SAME MODIFICATIONS FLOW MASTER 50 SERIES
SAME LIFT, SAME TIRES/WHEELS, 342 GEARS .
I KNOW THE ZR2 HAS 323 GEARS W/10 SPEED TRANY BUT THE ENGINE ALSO RUNS AT 1650 RPMS VS THE TRAIL BOSS AT SAME SPEED 1850 RPMS 76 MPH
(-200) RPMS SHOULD YIELD BETTER FUEL ECONOMY...
 
Traded mine in with 14k miles, lifetime average was 14.5

As has been stated, lots of threads and EPA seems pretty accurate based on my experience. I simply don’t believe any major outlier posts where folks claim to be getting crazy good numbers, simply not gonna happen in these trucks under remotely “normal” circumstances
 
I've got about 9500 miles on mine. About 50% highway and 50% city and dirt roads. My average is 12 mpg. I've seen sustained mileage of 22 mpg in flatter roads with no wind. I've seen 10-11 mpg in town in traffic. It's fairly easy to get 18 mpg on the highway at 70- 75 mph. Wind, hills, and start/stop traffic will kill the mileage. Also, if you do a lot of short trips say 10 miles or less, the average will always be low. Seems like the computer doesn't like to get the average up until about 15-20 miles.
MY TEST WAS MY DAILY COMMUTE TO WORK IS 48 MILES ONE WAY THE NO OTHER STOPS 76 MPH ON THE CRUISE CTRL
AVERAGE AT THE EDGE OF TOWN WAS 14.3 IT DROPPED IN TOWN A LITTLE
 
MY TEST WAS MY DAILY COMMUTE TO WORK IS 48 MILES ONE WAY THE NO OTHER STOPS 76 MPH ON THE CRUISE CTRL
AVERAGE AT THE EDGE OF TOWN WAS 14.3 IT DROPPED IN TOWN A LITTLE
Try it at 68 mph and report back. I have had previous trucks that got decent mileage below 70 mph and not so good over 70 mph.

Also fuel up with premium 91-93 at a different station to eliminate poor quality fuel.

If that doesn't give you different results, run it into the dealer and ask them to perform some diagnostics. Could easily be fuel trim or air intake calibration issues. They have equipment to check all the fuel, air, and emissions specs. Otherwise it's just arm waving!
 
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MY TEST WAS MY DAILY COMMUTE TO WORK IS 48 MILES ONE WAY THE NO OTHER STOPS 76 MPH ON THE CRUISE CTRL
AVERAGE AT THE EDGE OF TOWN WAS 14.3 IT DROPPED IN TOWN A LITTLE
You also shouldn't really go by the DIC. Do the math when you fill up. Doesn't really matter if the DIC is showing 9 or 19. Use a tank of fuel then just hand calculate it. Odds are it will be 14-16. I tracked mine of the first 10k and it was 14.8. Some get lower because of just short trips and all in town. But with mixed driving that's about where you will be. Short of changing the bumper and tires. Not sure you can really do much.
 
You also shouldn't really go by the DIC. Do the math when you fill up. Doesn't really matter if the DIC is showing 9 or 19. Use a tank of fuel then just hand calculate it. Odds are it will be 14-16. I tracked mine of the first 10k and it was 14.8. Some get lower because of just short trips and all in town. But with mixed driving that's about where you will be. Short of changing the bumper and tires. Not sure you can really do much.
DID THAT, AND IT WAS 14.1 SORRY I FAILED TO MENTION I MANUALLY CALCULATED IT SINCE IT CHANGES ONCE YOU HIT A FEW STOP LIGHTS
 
Try it at 68 mph and report back. I have had previous trucks that got decent mileage below 70 mph and not so good over 70 mph.

Also fuel up with premium 91-93 at a different station to eliminate poor quality fuel.

If that doesn't give you different results run it into the dealer and ask them to perform some diagnostics. Could easily be fuel trim or air intake calibration issues. They have equipment to check all the fuel, air, and emissions specs. Otherwise it's just arm waving!
YES I ALWAYS RUN 91 BUT I DO FUEL AT THE SAME PLACE EVERY TIME
I DID FIND SOME 93 I FILLED UP WITH AFTER THE TEST . I WILL REPORT IF I SEE ANY CHANGE
 
As AXE mentioned, run it into the dealer

but at 14.something mpg…I fear you are in the ballpark man. Differences in altitude, fuel, temps, elevation, and wind all matter and can sway it a few tenths…which puts you in line with the rest of us.

Mileage simply isn’t in the cards for these trucks as has been debated for many posts on this forum.
 
NEW TO THIS SITE:
NEW OWNER OF A 2023 ZR2 LOVE THE TRUCK BUT THIS FUEL MILAGE IS REDICULOUS!
I HAVE HAD A 2014 GMC AT4 (6.2) SINCE NEW , NOW HAS 82000 MILES HIGHWAY 20-21
CITY 15-16 RUNS GREAT ALL AROUND GREAT TRUCK 0 MODIFICATIONS...
NEW ZR2 13 CITY 14.1 HIGHWAY 3000 MILES STOCK
ADDED A 50 SERIES FLOW MASTER NO CHANGE : ( SOUNDS GREAT POWER IS AWESOME)
WHAT HAVE YA'LL DONE TO IMPROVE FUEL ECONOMY?
Come on now...you bought a ZR2 with a 6.2 and you're concerned about mileage??? If you can't afford the gas, maybe you bought the wrong truck ;)
 
TB’s run smaller tires, are a few hundred pounds lighter and still have a somewhat aerodynamic fascia. “Normal” 6.2 trucks beat the ZR2’s by 3-4 MPG.

14-15 is pretty standard for this configuration.

Swapping highway tires on is a net of 2 MPG on their own.
 
Hell the flow tie and that wide open grill are worth -3 mpg. You're letting in massive amounts of air and there is no where for it to flow. The flow tie should have it's own two barrel exhaust!
 

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