The two models are generally about the same size, with older Audi A4 variants being, indeed, slightly smaller than the A5.
Curb weight of Audi A5 Coupe is between 1390 kg (3064.43 lbs.) and 1695 kg (3736.84 lbs.), and gross – between 1895 kg (4177.76 lbs.) and 2210 kg (4872.22 lbs.), depending on the variant.
Sportback, Coupe, and Cabriolet variants generally perform equally well in terms of speed.
Output could be either 231 Hp and 500 Nm of torque or 286 Hp and 620 Nm of torque, depending on the modification.
In some cases, yes, but not necessarily. The lowest fuel consumption in the range - 3.7 l/100 km (63.57 mpg), is actually achieved by the 2019 Audi A5 Coupe/ Sportback (F5, facelift 2019) 35 TDI (163 Hp) S tronic variants, that do not feature mild hybrid technology.
Yes, all second generation facelift variants do feature LED headlights as standard, while Matrix LED headlights and LED rear lights remain optional.