Best strategy for reward tix DTW-LHR with 4 SWU's
 

I am a first time recipient of 4 SWU's via my platinum status granted through Amex Centurion. I'd like to try to use these in the Fall (Sept/Oct) to go DTW-LHR on a Wed-Sun trip. Ideally would like to find the best combination of approximately 200,000 banked miles/SWUs/$ to get there. 2 travelers. I've read the sticky thread on low tier business awards, but still searching for best strategy. Any help greatly appreciated. Thank you

I don't believe you can use all three, it is either M fare plus 1 SWU each way or M fare plus miles. This is assuming that there is available upgrade fares on your flights.

You may want to sign up for Expert Flyer - you can then search for Z availability. If Z is available, you can upgrade a YBM fare with SWUs or miles.

Don't forget that SWUs expire, unlike miles. If you don't forsee another use for them (besides perhaps domestic use), then it might make more sense to upgrade with those.

You may need to search for a while to get low BE award tix. If you can't find them, I think your most cost effective way would be to book two tix in premium economy (Premium Voyageur) on Air France and upgrade using your SWUs. You'll need to make sure that the segments have "O" inventory on AF and you'll have to connect through CDG. See this thread, TATL Upgrades using Skymiles and SWUs on Air France/KLM for more info.

Thanks everyone! Very helpful

Can you also search via kvstool?