I have just recently got myself a V36 type S coupe and from what I've worked out, the speedo reads 7% higher than actual speed, so upping the tyre size a little wont make the speedo read incorrectly.. And from what I could find on here in the Skyline V36 coupe - Wheels offset fitment section, I came up with this sizing.. but some of the info is a little misleading and confusing as the sizing's often say lowered on coilovers and yet others don't mention anything at all about being on stock suspension.. (or maybe I'm just easily confused) lol.. So thinking I was being clever, I got some Nitto Invo tyres at 245/45/20 for the front and 275/40/20 for the back.. This however was an expensive mistake (over $3500.00), as they rub like mad, both front and back a lot more on the back, they're just way too big.. (my bad).. This being said it did make the speed and speedo read correctly.. lol But it also makes the car look terrible (think 4wd rock climber.. pic below)..
Ohh and the wheels are TSW BATHURST, 20x9 et30 for the front and 20x10 et40 for the back..
But from what I see as far as where they were rubbing, I'm now looking at trying 245/40/20 265/35/20.. So I guess we'll see..