My wife's 09 Impala's dipstick has 4 bumps on one side and 4 dimples on the other. When testing oil level today on bump side it was at the lowest bump BUT on the opposite side it was at the very top. Now is it full or is it at the very bottom and needs oil??

 

read the dipstick from the lowest oil level point...after the engine has been off for at least 10 minutes, vehicle level. if you add oil...let it drain to the pan for 10minutes before reading the dipstick.