Here in the US in Illinois I got 29 mpg on my Ford EcoSport 2.0 AWD in Summer but only 24 Mpg now that we are into Winter temps. In contrast, our 2020 RAV4 AWD got 33 Mpg this Summer as 30 Mpg so far in colder temps. Every engine is a bit different in how it reaches peak temps internally in colder weather. Some just do not do as well in colder climates. Gasoline formulations hurt too as they become more volatile in Winter for better starting. Not much you can do to change this effect other than limit idling and long warmups and start driving ASAP because a load on the engine causes it to warm up faster.