Oil pressure question...I promise it's not another "who likes what' thread!

Just found this on the internet, but I guess we can't believe everything we read there:

Oil weight, or viscosity, refers to how thick or thin the oil is. ... Your engine needs oil that is thin enough for cold starts, and thick enough when the engine is hot. Since oil gets thinner when heated, and thicker when cooled, most of us use what are called multi-grade, or multi-viscosity oils.

Viscosity index improvers make sure oil thins less, it does not make it thicker than when it was cold (my interpretation). Or maybe we are all on the same page. I could be mis-interpreting posts above in #31 and #33.

What do oil viscosity numbers mean? Learn about motor oil, synthetic oil and regular engine oils..