What did you do to your NNBS GMT900 Tahoe/Yukon Today?

iamdub said:

ACC FTW. I've used their products quite a few times. Quality stuff.

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I even contacted OC to make sure they’re ACC products I was buying and they said they were. And the packages are shipping directly from ACC according to the tracking. I have always used ACC stuff, always fits great.

iamdub said:

A buddy that tunes has mentioned it to me a few times over the years. ...You know anything of this?

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Nope. Maybe @randeez Randy does.

iamdub said:

A buddy that tunes has mentioned it to me a few times over the years. My fill-ups happen every 3-4 weeks, so I just thought it was the older gas going a little stale. I'm always feeling more response and "oomph" after filling up so I've never really questioned it. The basic story as I understand it is that a timer (of sorts) runs from a fill-up event and the PCM adjusts accordingly if X amount of time passes without the float arm in the tank going back up. I doubt it has to be a complete fill-up, I'd imagine it to be a sustained specified percentage higher than where it was for it to switch tables. IIRC, he said its purpose was to account for the fuel losing some of it's octane rating as it sits.

You know anything of this?

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I'm not buying that I used 1 year old gas with no issue or power loss....it was E10 fuel as well 91/93 octane is the lest used so it could have been sitting in the tank for a while for many many months.. without a reload... they put in 5-6k gallons at a time. when you see a double tanker one is 91/93 the other 87 any other grades are blended at the pump

BG1988 said:

I'm not buying that I used 1 year old gas with no issue or power loss....it was E10 fuel as well 91/93 octane is the lest used so it could have been sitting in the tank for a while for many many months.. without a reload... they put in 5-6k gallons at a time. when you see a double tanker one is 91/93 the other 87 any other grades are blended at the pump

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Where do you come up with one year versus 3-4 weeks of time between fillups? Vehicle tanks are vented thru a controlled system, not open venting. I store my boat over winter with premium (non-ethanol) over the winter with no loss of power.

Also stations get regular tanker fills so they have fresh fuel to blend the 93 to get 89 octane. Not months without delivery.

The PCM checks for knock and then adjusts to a lower table if needed.

swathdiver said:

Nope. Maybe @randeez Randy does.

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no idea

randeez said:

no idea

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Ok, thought you might have come across that while tuning.

swathdiver said:

Ok, thought you might have come across that while tuning.

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Nah tank in mine only lasts about 3 days max

avalonandl said:

Where do you come up with one year versus 3-4 weeks of time between fillups? Vehicle tanks are vented thru a controlled system, not open venting. I store my boat over winter with premium (non-ethanol) over the winter with no loss of power.

Also stations get regular tanker fills so they have fresh fuel to blend the 93 to get 89 octane. Not months without delivery.

The PCM checks for knock and then adjusts to a lower table if needed.

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on the 5.3 push rod 93 will not make much difference unless in AFM mode.. that is the only thing it will improve .

unless it's a gen5 with vvt or gen4 4.8l/5.3/6.2l with vvt

another thing is Many gas stations will scam you and give you 87 octane at the 91/93 pump
it happened at 6 gas stations i went to. AND they were name brand stations BP/arco and Shell stations...

the only way to verify it is checking the ignition timing. with the obd2 reader...when it happens .. That is how i figured out they scammed me...


91octane can get upto 42 degree advancement mid 30s on average....
AFM can run long periods at 12-16 degrees advancement.


93octane can get upto 42 degrees advancement high 30s on average


87 octane could barely do -12 to 12 degrees advancement
no AFM may cause knock or loop of death





i had fuel sitting in my car for a year when the tras went out it still started

used as the neighborhood bait car as there was a string of break ins caught them on the 3rd time (left the door open with the alarm on) they got too greedy.

If you're filling up with good quality gas, it takes longer than a month for it to go bad/"stale". You can let good gas sit for 3-6 months without any issue at all.

Rocket Man said:

I got them from www.ocautocarpets.com. Last time I ordered from www.stockinteriors.com but they’re both distributors for ACC (Auto Custom Carpets) who is the manufacturer. OC was cheaper by about $50 shipped on the carpet which paid for half of the mats that have a maroon bowtie embroidered in them. I went with plush pile carpet with mass backing for maximum thickness.

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Thanks for supplying the provider.. I've looked at the other website before. This is something I'd like to do.

Will you photodocument the process. Seems easy enough. I can live vicariously through you for the time being