Request advice on this question: Departing very light weight on long runway (737) and perhaps for monitoring requirements, full thrust is used. The BRW is many tonnes less than even at the maximum assumed temp (say 55C).
Old Boeing manuals state that you should use V speeds for actual weight. On the other hand one performance engineer told me that is not so - that you use the V speeds for the actual OAT - even though they may be 20 knots or more higher than those for the actual weight. Seems a bit silly to me.
Why force the aircraft to stay on the runway longer than necessary. Also more chance of greater tyre wear and tear coupled with marginally greater risk of tyre failure at higher speeds?