because it really shouldnt be up to the line has a tendency to blow out or leak out. thtsa why their are hash marks between the full and add lines its the safe zone. the 12 they refer to is a dry system. unless you drain it for several hrs and shake it out, you never really empty 12 quarts. dot hates oil leaks

 

Maybe mine drains a lot more out, but mine is about 3/4 up safe with 3 gallons/12 quarts, which is perfectly fine to me. I usually leave the plug out for like 30 mins though.

 

I check it so I can tell later on if I'm using oil or gaining fuel.

 

When I do a oil change and add 12 quarts total, the oil is usually 1/4 inch above the full mark.

 

When I have my oil changed, they install all 3 gallons of oil and after it sets overnight its right at the full mark on the dip stick. I would hate to pay for an oil change and have them only install 11.5 qts of when your paying for 12 to be installed. But then by them doing so they make more $$$$ cheating customers. Another way to look at it if they service 10 cars/trucks and short each one 1/2 qt they save 5 qts of oil and that adds up at the end of the month. BTW I know of one place where the service manager told the lube guys short fill every car 1/2 qt of oil and had some bogus reason why and did so even if they used the customers own oil. Oh they would give the customer back the 1/2 qt of oil.