How much oil?

id recheck it again at operating temp. let it sit for a few mins after shutting down. too much oil is worse than too little. mine says 5 qts as well (all except turbo, which is 5.5 qts. also remember qts are different that liters.
liters are a bit less than a quart ( but not enought to make much difference)
also make sure the dipstick is all the way in place when you check.
better to be safe than sorry :)
as long as its in the safe area your ok
just my opinion