From my experience, changing the viscosity of the oil made no noticeable difference.I replaced my 24v oil sender last year as I was receiving no signal at all, still no signal, then got my oil receiver fixed by gauge shop, now it works.
Hot idle hangs low, and driving it sits in lower line or just a fraction below the lower line of normal range, would prefer to have it sit higher for peace of mind.
Thinking of putting a 20/50 oil in and see if that makes any difference