I didn't say it handled better lol

I can't comment on that as I ain't driven one

I was thinking changing up into second the derv has more weight to push down on the driven wheels hence more grip, I reckon the 16's would grip better in a striaght line due to the width of the 17's tramlining but in the corners the 17's width would win the day. I find unless your loading up the shocks with a bit of power the rs is a little skitish anyway.

ANother thought is that the derv has less overall power so handles better on it's on own limit if you get what I mean (I'm not sure I do !!)

I am no expert and just thought all this while sat here, and therefore could be talking out of my fat dozy ass lol:)

Out the box they both run 205s; 225s on the RS is a mod.

Bloody ell Ken dig up a dead 'un lol

Not srictly true, iirc some rs's came with 225/45/17's from the factory, so you could call it standard fitment, sort of

225s might give you better dry and/or damp traction (depending on compound) but I'd reckon you'll get more of an inclination to aquaplane. Certainly, the Dunlops had well and truly had it in the wet before they got to 3mm.