Since the question sometimes comes up on here "what can I expect from a T4 in terms of mpg?" - here's a datapoint.

900 miles in the T4 at "French motorway" speeds - gave me 34.3 mpg on supermarket 98. I'm quite happy with that.

Best I ever saw from an 850 T5 was a lot lower than that, and even my Phase 1 V70 would struggle to maintain 33.