The oil pressure should sit at three at start up as she warms up it can go down to .6 bar before you should be concerned the lighter the oil the lower the pressure most of the time (synthetics also tend to lower the pressure but only marginally). At park running and engine warm .6 to three is fine as long as it goes straight to 3 on acceleration. Hope this helps. 5w30 is a light oil i would use 10w 40 as a minimum unless you live in the very cold climates. Do not mean to get an oil discussion going. Personally I like mobil15w50 as it covers my area's temps very well. A oil sensor can give wierd readings so that is a good place to start if you are concerned. My 560 sits at 2 bar in idle warmed up.
m

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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)