I've seen double the fuel use than what I'd expect on similar stretches, when using AC on full tilt in very hot weather
That's city driving , ie lots of stopping, accelerating, ... and a small car / small engine where you can really feel the difference when accelerating with or without AC.
Out on the motorway or open road, the difference is far smaller and vanishes in normal variance.
With a 2,3L and thus 2.3 x bigger engine, you should see little effect
On average, AC cost 4% more fuel for me
0.15 kg/100km extra on 3,67 kg/100km overall average
(0.15 rather than 0.12 as the average also includes 1/6th mileage with AC on)
