I used to have my oil changed at a reputable lube shop near my house in Mi. However I moved since then and the last few times I have changed my oil in my 2018 Silverado 5.3L, I have put in 6.8 qts. The dipstick was at the top of the cross hatches showing full after a start and run for a few min. Now, my issue with this 8qt business is the problem with over filling the crank case. I am not a certified mechanic but would this not cause serious cavitation and poor oil circulation in the crank journals? Unless the incorrect dip stick was installed in all the Silverado, GMC vehicles we should only fill to the top of the crosshatch and that comes out to 6.8 qts. I can see a litlle overfill is ok but to be 1.2 quarts over seems as bit high. Just my 2 cents. I am pushing 100,000 soon. Knock on wood... have never had a mechanical issue to this day related to oiling.
