At idle the gauge can read anywhere from .7 to above 3 if I am correct.
When on the gas it should read above 3 always as far as i know.
My car at idle is usually at 2-3 and under acceleration always at 3+. It does dip down occasionally at idle below 2 if I am sitting in traffice long enough.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.