Haha, yes I'm doing the same in my 184 - when you work out what 5+mpg over 15,000 miles can save you at nearly £2/L! why wouldn't you.
I now generally stick to 58 - 60mph - which sounds slow (and feels it at first!) but actually when you time the journey it's literally a minute or two slower for my commute! 1x red light can cost more time!
57 is good for such a short journey.
I usually get 60-62mpg on my 25mile work commute 70% dual carriage way at 60mph 30% negotiating traffic. If I only get 55 I guess its done a regen.
My long term ave is also around 62 - I think it was more like 52-55 last year post lock down - but pre stupid prices!
I have got 70mpg a few time now - first time I let out a little 'yip' and nearly work my sleeping girls up in the back

above 70 I find is rare, my best ever for a trip being 74mpg on a 25mile run back from the inlaws. I think the wind must have been with me -
I find on a 20+ mile run;
Above 60mpg is quite easy with sensible driving as long as its not regening, although the other week we went to the beach for the day - 120mile trip - and I wanted to get there so sat at GPS 70mph and still got 66mpg!! I think it must have been down hill with the wind behind me!
Above 70mpg requires some effort - good traffic - green lights - no rain - little wind
I'm using standard 32ish pressures, and normal throttle - with sport steering - tried ECO but didn't really find any noticeable difference.
My rules:

less than 60mph - unless going down hill with free acceleration.
NEVER accelerate going uphill - I actually back off a little.
I use cruse control but only on the flat. Constant speed going uphill is equivalent to accelerating.
Try to gently accelerate going down hill when I know there is an uphill next to use my momentum working with gravity.
Try to avoid driving at busy times.
Avoid driving around my local town. Always walk or cycle.