Citroen saxo 1.1 oil problem

[startx]

Saxo 1.1 supposed to take 3lt engine oil without the oil filter. When i put 3lt the indicator shows tha there is more oil than required plus the car does not run smooth(there is a lot of oil in the air filter). When I put 2.2 lt oil the indicator shows OK and the car runs perfect......
What the hell is happening! Running with less oil can be a problem?

[KebabMeister]

You area using the dipstick to check your oil level?

[verrecchia]

the enginbe takes 3ltrs form EMPTY, never overfil and engine it's worse than running low on oil, use the dipstick to check the level, and only put oil in if the level falls BELOW the minimum mark, and then it should only need about 1ltr, MAXIMUM, pour the pil in a little at a time, wait about 1 munute and recheck on the dipstick, continue to do it this way til the oil level is about half way between min and max on the stick, absolutely no more than the max level mark if it is, then drain the excess off