Mine is nearly at " O " as well too when idling in drive,*IF* the engine temperature is around 85-88*C - which is the highest I have ever seen it, but by 1500 RPMs- it is back to "3", which I heard was normal. When around 80*C, which is where it is usually at- the oil needle is around .5 .

When idling in park when the engine is fully warm @ around 85*C, it is around the "1" to "1.3".

I am hoping a new oil change and a MB filter will increase my oil pressure, but perhaps my sending unit is in need of replacement as well - or the engine. I do not even care anymore.