New member/new Tahoe owner here (2010 LTZ)! Loving it so far, but getting the runaround on a repair quote and also have a few questions in general.

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Full Access Member
Mar 9, 2023
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My Yukon XL weighs about a 1,000 pounds more than yours and gets 12.6 MPG with 100% city driving and averages 15.6 mpg with 50/50 city/hwy driving. That's 1.3 to 2.2 gallons per hour running around town and such.

2010s seemed to have unique tuning and got better mileage than all the other years.
VERY interesting!

I just looked at a stock 2010 tune vs my 2012 and there are some differences!

The engine side has a few seemingly small changes, O2 rich/lean vs airflow and some stoichiometry settings...

For the transmission, there are MANY small differences! Shift patterns have some small tweaks, but it also has an extra map that says eco mode. I don't know if that map is even used, I have 4WD maps instead. The torque converter clutch apply/release maps, apply ramp and slip tables.. Shift times and inertia profiles.. many small differences..



May 4, 2016
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The milage question from earlier … This will make you feel good about your economy w/ the 5.3 Tahoe. Our 09 Esky gets 11-13 & 8-9 city. On e85 which is what I usually run it’s 10-12 & 7-8 city.

I have a lot of hills and idle time that accounts for the low numbers. The e85 benefit is crazy clean oil, lower rpm shifts & longer oil change intervals. Here’s a comparison tool so you can plug in local gas & e85 prices to calculate savings.

We saved enough in 3 years to pay off the $14k price of the truck. Damn, the cool e85 vs gas price comparison tool is yanked off the internet. I was going to post it.


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Nov 7, 2017
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Stockton, Ca.
Shop raised a red flag about my oil levels while doing their "complimentary inspection" yesterday, said that I was close to 2 quarts low.

Changed the oil about 2000 miles ago (first oil change under our ownership) and I know for a fact I put 6 qts in it. However, I admittedly forgot to check the level on the dipstick afterwards (usually routine for me but I think I was in a rush, my fault entirely).

There are no visible leaks underneath the vehicle or in the engine bay, and there's no obvious burnoff in the exhaust (don't see or smell anything unusual). I also seem to recall reading that we have a low oil level warning that kicks on at 1.5 or 2 qts low, which hasn't happened.

This is what the dipstick reads after sitting for 24 hours in 25°F weather. Seem like a major concern to y'all?

Gonna change the oil again this week and of course keep a hawk's eye on levels, but just figured I'd toss this out here in the meantime. I do understand that there's some consumption to be expected with the AFM, correct?

View attachment 425314
that level right there is right about 3/4's of a quart low, if 5.5 came out then that would make sense these usually take a hair over 6 quarts, I know spec say's 6
2qrt's low would be bottom of the stick
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