Hi Everyone!
First post here.
I have a 2020 K1500 Silverado High Country 3.0 diesel. Bought Jan. 29th, 2020. I now have 8,900 miles on it. I did my first oil change at 3,800 miles. Sent in a sample for an analysis from Blackstone Labs (Ft. Wayne, IN). All was good.
I too, had the same issue of running more than a quart low. Checked the oil level when I got it a few times. Let it go for about 1,500 miles and was shocked when I checked it again at 2,500 miles (it was low.....didn't even register)!
I did my first oil change on my own and took some video of it. I bought 8 quarts so I'd have an extra. Nothing earth shattering or new as it the usual drain plug and oil filter (remove, drain, clean, re-install). I did opt to go with a Wix oil filter vs. the AC Delco. Since that oil change I have added the extra quart as it was not registering again. I'm presently in the low 30s on oil life per the DIC.
So far, the best price I've found on the oil is $4.70/ quart from https://www.tascaparts.com/oem-parts/gm-oil-19370138. Like most of you have experienced, the supply is limited and I found and bought the oil for my first oil change from https://www.cheapestgmparts.com/oem-parts/gm-oil-19370138 as they were the best price and in-stock at the time (May).
I'm hoping the oil consumption will stop soon.
I'll rotate my tires with this next oil change.
Overall, I love this truck. Mileage is incredible compared to the 2010 I traded in!!! I'm getting 22-24 mpg in town and 28 or so on the highway. DIC says the best 50 mile segment was 33 mpg!!! I do keep a log of my fill ups and the DIC measures from 100% spot on to upwards of 1 mpg low compared to hard numbers. If you're interested, you can follow me on Fuelly.com for my milage experience. I go by SWBuckeye there too. FYI - I use the TFL fill up method....pump kicks off, wait 30 seconds, start & let it kick off again.
Not sure if anyone has experienced this but I had a "Service Emission System" light come on? Ended up getting a new back pressure valve on the exhaust system to replace the original. No problems since.