I have just seen a set of 20" alloys from a 2014 RR Sport that have 255/55/R20 Pirelli Scorpion Verde fitted on them.

I currently have 19" original alloys from and SE which are the spoked alloys fitted with 255/50/R19 Pirellis

Would going to a 20" cause any problems with the speedo reading or anything else?

many thanks for reading and looking forward to the reply

Regards

Bit of a strange size there normally 275/40/20 or as some people do change to 275/45/20 for abit more sidewall.. The size your talking of changing to will be taller so will affect the speedo reading though don't know by how much. 2008 G4 RRSport TDV8 current
2009 TDCi 90 current
2018 Discovery 5 HSE lux current
1994 Dakar current

Being the L405/494 size, 255/55/20 is quite a bit bigger meaning the speedo would under read by approx 6.46%. On a facelift I think you are able to correct for this via the CCF (the settings are there but I don't know if there are limits on them etc.) if you should think it necessary. Couldn't comment on the physical fitment though (it'd fit a D3/4 which takes "a size up" from the RRS but I'm not sure if there are bodywork differences that'd affect it).  Visiting from DISCO3.CO.UK
2006 Discovery 3 TDV6 Auto HSE Zambezi Silver