Hi I have fitted a K&N Air Filter to my 308sw GT 180 2016 updated maps and software to latest versions the filter is by far better than standard filter on a round trip of 331 miles mixed driving the dash screen showed 64.2 mpg I know its a guide and that the true way all about filling car to brim then after trip refilling but its a good guide I also tarted it up by fitting a Shark Fin Antenna looks the part.