Three tank Robin
The three tank Robin DR400-180 is very good from a fuel management point of view.
The centre tank low fuel warning tells you that you may not be able to make a go-around with that tank selected, but it gives you a safe 20 min to dry warning in level flight at 75 % power.
The wing tanks give one hour of fuel each with a 5 min warning to dry tank.
I usually run the main and one wing tank almost dry planning to be on the ground shortly after changing to the full wing tank that I know has an hours fuel in it.
With the 180 fitted with the supplementary tank (under the baggage bay) the aircraft in more than happy to get as far as Northern Spain non stop from South Oxfordshire. I feel much more confident with the fuel management on the Robin than on my PA28 because the fuel usage can be much more closely monitored on a four tank aircraft.
NOTE all the numbers are for the 180 aircraft, the 160 should burn slightly less fuel.