50 MPG is even more amazing for a GTI then!
£37 @ 116.9 is 6.96 gallons so 244 miles is 35mpg
£35 @ 119.9 is 6.42 gallons so 325 miles is 50.6mpg which is a 44% improvement.
I do about 50-55mph on the M1 on my way home from work lately to try and stretch the diesel a bit further. I drive to work slower too but don't always set off early enough to drive that slow and still get there on time.
though they're all called RON...