These coolant temps and corresponding
oil temps mirror what I can reproduce in blown Modmotors. Running a coolant temp of 180˚F (engine not fully warmed up) produces an
oil temp of almost exactly 20˚F less (160˚F) when the car is idling. If you do repeated aggressive acceleration events, the coolant temp can momentarily go above 190+˚F, although it is regulated to a 190˚F temperature. The corresponding
oil temp will be ~170˚F, maybe 180˚F on a hot day.
Many of the internet oil temp wizard websites will tell you the oil temp should be in the 220˚F to 230˚F window. To get my oil temp that high, I need to run my coolant temp up to 240˚F (possibly higher) — which I do not feel comfortable doing. Here is an engine life expectancy table from Performance Unlimited that I saved a number of years ago — it is interesting. It argues for a 175˚F to 195˚F oil temperature for the best engine life?!?!
Additionally, because of the screw blower I use, ~240˚F coolant temps raise my in manifold IAT2, Intake Air Temperatures into gasoline's detonation danger zone, which I fastidiously attempt to avoid.
My personal preference favors Mobil-1 0W-50 oil with a 190˚F engine coolant temperature, which forces the oil temps into a cooler range than most experts today claim is optimal. I think, in the end, this comes down to personal preference. None of our engines are 100K mile operating time, candidates. The oil temperature debate appears to focus on extended component life in an operating environment (100K miles?) that we most likely do not live in and will not live in.
Use quality oil and do a Blackstone Labs oil analysis at each change. If your Blackstone Labs oil analysis comes back thumbs up, I would put the worry beads away — you're probably as good as you are going to get, or more practically can get. Time to enjoy your Attitude Adjustment Toy and forget about the experts.