when i drove my 250 daily i used both fuels
it's not the fuel consumption it's the actual power delivery and how the car ran
on E10 it ran like dog *BLEEP* very rough. idle flux during idleing at lights
once i changed back to 98 it made a marginal improvement.
lag between throttle power deliveries in high rpm. E10 failed to get a tick with me.
our cars run very high compression and to be safe ill rather use the best aussie fuel suppliers can supply. lol
some times i even use ocatnce boosters to give my fuel system a bit of a clean lol