^ That's for the manual - how much more do the S-tronic gearbox-equipped models weigh? The 458 is penalised in its weight stakes by the heavy dual-clutch transmission.
The weights for the facelifted R8 to EU1 standard are as follows:
V8 4.2 FSI quattro
Manual 1,635kg (263hp/tonne)
S tronic 1,660kg (259hp/tonne)
V10 5.2 FSI quattro
Manual 1,695kg (310hp/tonne)
S tronic 1,720kg (305hp/tonne)
V10 5.2 FSI quattro plus
Manual 1,645kg (334hp/tonne)
S tronic 1,670kg (329hp/tonne)
And for comparison, the 2011 R8 GT.....
R-tronic 1,600kg (350hp/tonne)