1-11 perf
Really straining the memory for this but if I recall correctly on a standardish day, still air RW26 at Luton gave an RTOW of 43610kgs (13 flap dry). Using demin water allowed a takeoff at max structural weight of 45200kgs (also 13 flap), so a benefit of 1590 minus 320 kg for the water =1270 kgs of extra fuel or payload.
We did have an "Optimised V2" procedure ("Improved Climb" to Boeing pilots) which IIRC gave an RTOW of about 44500kgs, but there were restrictions on its use, although I don't remember what these were. Anybody?
I always loved the noise!