Will gas mileage improve? 06 1500 z71 5.3 flexfuel

[Need2Know]

I just got this vehicle and it's a great truck. It's been a while since I've had a truck and it's nice to be back in a chevy.

 

Have just reached 300 miles and steadily heading toward the 500 mile break-in. Will gas mileage improve over time and past the break-in point?

 

How accurate is the computer mileage calculator? Hoping their's some fudge in there too and I'm actually doing better than what it says?

 

Otherwise I'm getting a little itchy seeing 11 mpg on that screen.

 

Maybe someone has some idea? Thanks.

[redvett]

To get your new truck fully broken in you will have to have around 12000 mi on it. The average mileage info is quite accurate but must be reset after every fillup to be correct.

[cmoore74]

I just bought an '06 Crew Cab Z71 with the flex fuel 5.3L. The gas mileage did improve. It was pitiful in the very beginning as you state and I seem to recall a similar MPG. I thinkit it took to about 1500 miles to start getting good.

 

I'm at about 5000 miles now and I get about 15 MPG around town and about 19 MPG on the highway. This is driving the truck moderately (easy but not grandma easy).

 

The computer unfortunately seems to over-estimate the MPG a bit by about 1 MPG. Acvcording the the computer I'm getting about 16 MPG around town and 20-21 highway, but when I use the trip and gallons to fill at the station I get about 1 MPG lower as stated above.

 

I am quite happy with the MPG. Before this I had a 2000 S10 4x4 and got about the same MPG as this one.

 

Also I'm quite pleased with the truck so far.

 

Be patient, the MPG will get better.

[Need2Know]

Thanks for the help and the info. I hadn't started really sweating and didn't want to start.

 

Why does it work that way and what's the reason?

[ktg]

I've got a 2006 Tahoe with 5.3L and about 7000 miles on it. The mileage keeps getting better. I've got a Wester's tune and I'm getting about 13 in town and 22+ on the road.

[cmoore74]

Thanks for the help and the info.  I hadn't started really sweating and didn't want to start.

 

Why does it work that way and what's the reason?

 

<{POST_SNAPBACK}>

 

 

 

The drive train is breaking in which is basically saying you get some initial wear on internal engine, transmission, differential components which is normal. In the beginning a lot of this is happening and the process slows after several thousand miles, however complete break-in is arguably tens of thousands of miles down the road. I think the biggest change is due to the piston rings setting, but I must admit I am no expert. I'll let someone else provide a more detailed explanation on this.

[Need2Know]

it got better, b/c my driving has gotten better.

 

now, however, i'm noticing a low speed squeal from the front end. only parts i can think of are brakes and cv's. braking applied or not, same noise. weird.

[Need2Know]

also, back to the mileage, does anyone use e85? what does it get?

[2007GMCSierra]

If you look at performance numbers when new and at 40,000 miles - the numbers will be better at 40K miles. Must be less friction within the engine and likely less friction throughout the drivetrain as thing loosen up.

[HuntingEd]

Its called "break-in" period for a reason, your drive train is breaking off all the intolerances from the factory.

 

Ive only got 400 miles on my new Vmax and have already started to see the mpg climb, Im up to bout 14.5 now, was down at 13.5 just a week ago... Should be gettin better too. Im getting 18-20 hwy, its just the around town thats suckin gas... not to mention that my foot likes the power

[rossn2]

Yes, I use the E85 fuel. You will notive a 20-25% loss in MPG due to having to use more of the E85 to maintain the same hp as with regular fuel.

 

Regarding the DIC. Try going about 40-45 mph on a level road and reset the DIC, watch the fuel mileage indicator go thru the reset process and you should see it go higher and level off. Then pick up speed to around 55 mph and reset the DIC again..

 

Mine will say 16-19 city and 19-21.5 highway. But after figuring manually, both combined is around 17-18 mpg and I drive pretty conservatively. Gotta remember the mpg stats are for 55mpg, level ground, no wind resistance. Once you go over 60, mpg goes down... If you add things like a front brush guard, front hood bug shield, nerf bars, etc you loose mpg too...