1.5 Civic turbo is much more fuel efficient than 2.4 Accord due to the lower CC, even with Turbo, and because of the lower weight.
The Accord has less bells and whistles of course, compared to Civic simply because the Civic is a newer car
Accord has larger cabin space (D segment vs C segment)

Theoretically yes, due to smaller cc. But i guess it depends on driver driving behavior and road condition etc

My opinion la~ 

Comparing CX5 2.5 vs CRV 1.5T more accurate as both are almost 1.6 tons car. Skyactive moderm engines are very efficient. and CRV 1.5T tune for more power than Civic 1.5T. Even honda website fuel consumption CRV 1.5T - 7L/100km while Civic only 5.8L/100km.

If you compare accord 2.4 vs Civic 1.5 T to have same fuel then is not accurate. Accord is much heavier than Civic (250kg extra) bigger tyres plus accord using older 2.4NA and not the high compression skyactive modern engine. + old 5 speed GB compared to civic CVT. If accord drive relax while civic drive aggressively then is possible to have same fuel consumption. If both have the same driving style then is impossible.

Civic 1.5 T highway @ 110km/h can achieve 20km/l + and my previous city 1.5 can only get only 18Km/l+. If accord 2.4 can achieve 20km/l @ 110kmh then is really impressive.  Means the higher the CC the better the fuel consumption. lol

are you serious bro? you drove only 28.6km.. and based on picture, you are on highway.. the most left lane, my guess ur speed not even 90km/h..  

actually i always drive alone with my wife only... parent in hometown one year come two or three times.... by the way i am 28 onl   
How was Civic t.5 tc highway drive ? after 120km still able to feel the power is still can power up?
so which one your prefer in the end?