I have a MY11 Supercharged, with 275/40R20's. The potholes in our roads have already cost me three tires. Can i change to 275/50R20"s ? If I do, dare i use my spare tire?

You could do that - you should be ok for size in the wheel arch when applying lock I run 255/55/19 which is only 20mm smaller than that in diameter and there appears to be enough room for a slightly larger tyre; you would need to heck carefully on full lock however.

You wouldn't want to use your spare for anything other than a short, slow drive in an emergency as there's a 7.5% difference in diameter so you risk annoying the transfer box and the DSC.

If you do want to go to 275/50/20 then buy a new spare tyre in that size too... 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Hi, can anyone tell me, can I change my wheels to disco 4 10 spoke 255 55 19 as I have brembo brakes

I would change to recommended size of 255 50 19. This will keep speedo and mechanical components happy. This will give the best ride and protection on rough roads  Wanted a Series 2 LR since childhood but previously owned MY16 Disco Sport HSE TD4 Auto, MY13 RR Sport Black Edition TDV6 Auto, MY10 RR Sport HSE TDV6 Auto, 2007 Freelander 1 Freestyle TD4 Soft Top, 2009 Freelander 2 GS TD4 Auto, 2007 Freelander 2 GS TD4, 2004 Disco 2 Metropolis Auto, 2002 Disco 2 GS, 2000 Freelander 1 SE TD4 SW

Still hoping for a S2 one day!