Hi KillaWhat,
Are you using Michelin MXM4 Tires?
It seems UK has different tyre models, I've spent half a day today doing research and most important factor I learnt is that noise level that is displayed (EU tyre label regulations) can be very misleading, as often the lower it is, the higher the interior/cabin noise, probably because the noise is directed inside the car, to make it score better outside. I'll try to blog my research results later.
In my case I've just ordered
Continental "Conti.eContact Electric" tyres (replacing Michelin Energy Saver Plus), and I must admit my curiosity is the main reason why I decided to buy it (£305 with fitting, 4 tyres), and I will update
my blog post with interior noise in 2-3 weeks time. I'm a bit skeptical, but reducing noise just by 3 to 5 dBs should be noticeable and maybe I will get a bit better range, I'm hoping for 3 to 5 miles extra (3-5%) per full charge. Will see how it goes.