Closer to 35 litres on refill. I wouldn't count on more than that You can fit an extra litre in the fuel neck..but not recommended

Having no kinks in the fuel hoses connecting to the tank will allow all of the fuel to be used. But it is bad habit to drive with less than 1/4 tank. I ran out fuel once due to the hose being too long, and allowing an 's-bend' effect to occur in the the fuel hose from the tank to a surge tank under the car.
I run a intank pump now with a swirlpot inside the 1200 tank.

I reckon close to 350kms per tank when I had the standard CA18det installed. I now have fuel wasting 270deg cams, so that's no longer the case. I'll have to let you know sometime soon, when the car stays on the road for longer than a tank of fuel