Yes to the weight.

I call the oil pressure very good for an old merc.
Hot at idle is about 18-20psi, any sort of increased RPM and it pegs the gauge. The oil pressure is more stable at very hot temps, such as after a long highway run, with the synthetic, also the engine coolant runs slightly cooler on the gauge. I've observed this before going from relatively heavy (15w40) dino oil to this weight synthetic on a handful of older motors. And plus it's $19 a gallon, which is a real plus to me.

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K