Brill, great results for your circumstances, and no doubt encouraging to us in the UK with distinctly average weather year round.It is a M3P- so 18" tires. 2" lower would not make it through our snows.
It's 47 miles round trip to work with about 42 miles of interstate. Trips are almost all interstate so 80% highway.
This includes winter months often below zero F with coldest days at -20F when range drops to 250 miles. And hot summer days near 100F that also kill range.
So if you live in San Francisco or London, your results should be much better.
Are you using stock tyres or something else/winters for winter?