I’ve just ran a Touran for the last three years, with the same engine. Around town we would achieve 23mpg but these were very short journey, on the longer runs motorway and A roads around 40mpg. This was acceptable for me as our annual mileage is only around 5k a year. Unfortunately there is no work around for how much fuel it’ll use. So if its getting financially difficult for you I would have a chat with motability and explain your situation and see what they can do for you.
Current Car
KIA Sportage GT Line Mhev
Previous Cars
Peugeot 5008 Allure Premium
VW Touran SEL
Citreon C4 Picasso