The empty mark is never accurate. It is always showing empty when there are many liters/gallons left in the tank. So nothing to worry about.

If you want a guarantee, do this: Put a spare gasoline/petrol container in the back. Drive until the fuel runs out. Check the guage reading. Then you know for sure. I've done this with most of my cars. Whatever the brand, I've had enough fuel for 30 to 100 miles left when it reads "Empty".