Avensis n47 2ww

[t27_bill]

Hello everyone its been a while since i have been on a forum im glad to say im back in the toyota club and hoping i aint chose the wrong avensis i have the dreaded bmw engine in my avensis its a 20!6 model with 119000 miles on the clock with full service history. Main issue i have at the moment is the fuel reserve light coming on to early its meant to have a 60 litre fuel tank after 300 miles the reserve light is on when i fill up it take between 38 to 42 litres meaning i have a reserve tank of 22 - 18 litres which i hate. I wanted to know if this is correct and if any of you guys have the same issue. I have toyota techstream but cant seem to find a way to change the reserve limit or if it can actually be done. Would love to know what type of mileage you guys get from this i average 38 to 45 mpg other than that i absolutely love it its a business edition so got half leathers auto wipers headlights and its a estate so a mega bonus for me.