A buddy of mine recently pointed out that when you type l/100km to mpg into google it uses US units for gallons, so that was why my mpg seemed so low. If you type in miles per UK gallon you get the 'proper' figure. It turns out that my average of 6.1 l/100km on the normal daily drive is actually closer to 46 mpg, rather than 38. I thought mpg in the 30s sounded a bit off

I'm not sure if the trip computer displays mpg or l/100km for you guys in the UK but it might be worth noting anyway.