[Vigilante375]

You could have air in the supercharger and thanks to GM, the car doesn't have an accessible reservoir. You can buy one for a couple hundred dollars and know that it'll keep the air out of the system. This could cause the engine to work more when the supercharger can't help and use more fuel.

You'll have to go to the dealer and ask them to bleed/purge the supercharger coolant system or by a reservoir and spend 15 minutes installing it or look up videos on YouTube on how you can purge it yourself.

I didn't pay attention to my MPG in the first few thousand miles but in the last 20k, I know I can get around 22 MPGs or more. That's with a stock A10, non 1LE. 30 minute commute to work with speed limits from 55 to 70.

I posted last time in another thread about the ZL1 gas mileage and I stated I was at 229.3 miles at 21 MPG and at just over 1/4 tank left. I can't say what the MPG was after full up because I just did a track day and the car will eat up 1/4 of a tank or more in 20 minutes while out there.

One other thing you and your friend could do. Is get out on the freeway, with no traffic around and race from 55 to 100. That'll tell you if your car is underperforming.

[Firecaptain]

OK.....I'll ask it......any chance there's a gas thief.......

[pauly1119]

Originally Posted by mariojas

And aero...

Yes very true, didn’t think about that.

[TXCSSU]

Originally Posted by Vigilante375

If you're just cruising down the road at a steady speed or just driving normally, you can be in Tour, Sport or Track and the car will shift the same and keep the same RPMs.

If your start to drive aggressively or so, then the car will shift differently.

Snow/Ice mode limits your throttle input and the way the car shifts so that is more smooth and not jarring the car. No matter if you're driving like old people on Sunday or if you're on a road course.

That's for the A10.

I figured given the OP's issue, he wants to make sure that both cars are set identical to eliminate any variation. I would even go so far as to make sure that both have the same PSI on all tires.

Originally Posted by Firecaptain

OK.....I'll ask it......any chance there's a gas thief.......

Lol, this is also a valid possibility. I wish the Camaro gas tank would lock with the doors.

[Mac7504]

Aren't most new cars made with an anti siphon device of some kind? That's why people are now drilling holes into the tanks.

[arpad_m]

Originally Posted by TXCSSU

Lol, this is also a valid possibility. I wish the Camaro gas tank would lock with the doors.

Well, the EU and AS export models do, the associated option code is N08... the slot for the lock pin is there on our cars as well, but GM didn't consider this option a necessity for the US model. You could wire it up yourself if you can source the components.

[FrostZ]

I don’t know if I am more proud or ashamed the fact that I’ve pulled off 32.1 MPG in the 25 mile average in my 19 ZL1. You can definitely make these things barely sip vapors if you really, and I mean really try.

[arpad_m]

Originally Posted by FrostZ

I don’t know if I am more proud or ashamed the fact that I’ve pulled off 32.1 MPG in the 25 mile average in my 19 ZL1. You can definitely make these things barely sip vapors if you really, and I mean really try.
Attachment 1095252

I have a best 25-mile average of 33.2 mpg (psst), but that section was slightly downhill for the most part...

Hope you weren't cruising at 46 mph in sunny weather on a highway, though

[FrostZ]

Definitely not! Was slowing down in a construction zone so it felt like a better time to take the photo. I was cruising about 65 on a smaller 55 MPH highway across NH headed to the dealer. I needed to bleed the inter cooler circuit after I cracked it open a few days before hand so I was keeping it easy incase air caused cavitations which shut off the pump for a few minutes at a time. ADM reservoir later removed that problem but it’s proof these cars can be comically efficient given the right conditions.

[george]

I doubt this plays a major role, but the Track Preparation Addendum for the manual states that in the first 1500 miles, fuel consumption may be higher than expected.

[KaMaRow]

ok so I was right something was wrong. So I did what everyone here said to do and I unhooked the battery. I left it unhooked for about an hour while I did other things. So the same trip I made down to my buddies house the second day I had the car which is around 56 miles I used right about a quarter tank of gas or about 4.5 gallons about 12.4 MPG on touring and on open road. Yesterday as I said I got about 11.4 to the gallon again on open road and in touring. Along with the bogging down feeling and slow acceleration.

Today after unhooking the battery you could immediately feel a power difference. I went to nearest gas station topped off and drove down to his house again same roads and in touring. This time I didn't even use a 1/8 of tank we stopped filled up again did math and this time I got 23 MPG ... MAJOR difference. Then we took it to a very winding very steep mountain road and we went down it and back up full beans pedal to the floor whining it out. I mean we gave it total hell like we were trying to win a race then took it on a normal road a bit. stopped topped off a again did the math and we got 18 MPG giving it total hell. and the acceleration and speed were off the charts.

So what ever was wrong and there was something. Unhooking the battery fixed it. I went by talked to dealer told them the story and all we can figure is the person who did the PDI drive, which was 3 miles they did, had to of done something wrong or it came from factory that way. Either way it seems to be fixed now cause now im getting better then the listed averages and if MPG only improves...

[KaMaRow]

Originally Posted by Firecaptain

OK.....I'll ask it......any chance there's a gas thief.......

LOL not unless they were running next to the car cause that was the mpg I was getting while i was driving it. and the gas levels didnt change over night so I dont think so...

[SATINSTEEL1LE]

When in doubt - reboot.

Glad it worked. This is something you should do after the climates change or if you add a simple mod like a drop-in K&N airfilter or something minor. The long term fuel trims need to be leaned from the short term fuel trims. They are a running average. Same way you would want to reset your average MPG on the dash before a long highway trip. You dont want the car to have to calculate the better MPG and slowly average it up as you drive. You want the real-time calculations happening in the current condition.

Resetting the battery both cleared the learned long term fuel trims as well as the learned shifting parameters. This happened with my 21 Z. It was new, but had 188 miles on it. It ran like POOP from the dealer. I logged it with HP Tuners and saw my LT fuel trims were -25 while crusing. The car was trying to pull 25% fuel out to keep the car at stoich. And once I cleared the LTFTs with the battery pull, the car was able to learn the new fuel trims with my fresh tank of 93 and me ripping it hard. They are much better now -5 and less, so the car is not having to try as hard to run correctly based off its factory calibration. So again, glad that worked for you.

[KaMaRow]

Originally Posted by SATINSTEEL1LE

When in doubt - reboot.

Glad it worked. This is something you should do after the climates change or if you add a simple mod like a drop-in K&N airfilter or something minor. The long term fuel trims need to be leaned from the short term fuel trims. They are a running average. Same way you would want to reset your average MPG on the dash before a long highway trip. You dont want the car to have to calculate the better MPG and slowly average it up as you drive. You want the real-time calculations happening in the current condition.

Resetting the battery both cleared the learned long term fuel trims as well as the learned shifting parameters. This happened with my 21 Z. It was new, but had 188 miles on it. It ran like POOP from the dealer. I logged it with HP Tuners and saw my LT fuel trims were -25 while crusing. The car was trying to pull 25% fuel out to keep the car at stoich. And once I cleared the LTFTs with the battery pull, the car was able to learn the new fuel trims with my fresh tank of 93 and me ripping it hard. They are much better now -5 and less, so the car is not having to try as hard to run correctly based off its factory calibration. So again, glad that worked for you.

Sorta like when you call IT. Did you try turning it off and back on again LOL