Mixing Oil Weights?

[Ironhorse]

Well seems along with every thing else being on the short list the oil I use in my '05 Tahoe 5.3 LS engine is added in locally here. I use the Quaker State Full Synthetic 5W30 Dexos2 per the owner's manual. Usually change my own oil /filter and the first time I changed oil I found out the capacity is SIX quarts not the usual Five I have been used to for so many years. Bummer having to be sure and buy ONE extra quart each time. Also use Wix filters when I change.

The Change Oil message has come on the DIC screen several times and I know the oil life percentage has reached 0% within the last week. Oil capacity is good on the dipstick, just about halfway to the first mark below full. Problem is can not find a 5W/30 one quart container. Bought the five quart jug okay, checked three local stores, no single 5W/30 to complete the six needed quarts. Closest I can find is a single 5W20 which I did buy. Thinking can't be much of a difference using the one quart of 5/W20 mixed with the five quarts of 5W/30. Any one care to share thoughts on this.

Hate these shortages in everyday products and items needed.