E20 petrol dropped my mileage ~3km/l — anyone else seeing this on older cars?

My 2019 petrol has clearly lost about 3-3.5% mileage since E20 became the default at pumps. Went from ~15.8 to ~15.2 on my usual office run, same route same driving. Bike also feels a touch thirstier. FADA themselves admitted pre-2023 cars take a hit. Fuel price didn't drop either so we're basically paying same for less range. Anyone logged before/after numbers? Curious if it's real or in my head.