I have got 245/75 r16 on mine. Mine fit fine but sum require 'camel cut' I guess it depends on the tolerance stack up of a few things when the car was made. In terms of the speedo, it is actually spot on now with the new tyres, before, like most cars, it was reading low.
245/70 I think are only 14mm larger radius than 235/70s that are fitted as standard on a lot.