Correct oil pressure?
 

Just a recp, I have a 1990 190E 2.6 and I run fully synthetic 15w-50 in my car. When it is operating at ambient temp and I am stopped at a light, the needle drops down and rests on the bar at "0" however as soon as I start to accelerate it climbs back up to "3" @ 2000 rpm. Is this ok? Is there a problem with the needle resting on "0" while I am stopped?

Thanks again everyone.