E20 and my tankful average: is the 5 to 7 percent dip real in your Swift?

Filling up this week I got curious about how much of my mileage the ethanol blend is quietly eating, so I went reading.

Spinny's E20 compatibility rundown says every Swift built after April 2023 is E20 compliant, with a 3 year or 1 lakh km warranty on running the blend, and that compliant cars still lose roughly 5 to 7 percent efficiency because ethanol carries less energy per litre. Non compliant older cars take a much bigger hit. And the supply side keeps shifting, which our own piece on BPCL's ethanol tender for 2026-27 gets into.

So here is what I want from you lot. Do you actually see that dip in your tank to tank numbers on the ZXi Plus AMT, or does it vanish into traffic and AC use? And has anyone noticed one brand of pump giving a steadier average than another on the same breakfast route?

I log mine by hand at every fill. Curious whether that is paranoia or useful.