Lindsay,
I just looked up the tyre/wheel sizes, looks like you need 245/45 x 17 not 235/45 x17 - 245/45 x 17 has overall tyre diameter of 652mm and the original tyre size was 654mm, so not much in it, if you went for 235/45 x 17 it would be 643mm smaller overall wheel and tyre so the speedo would over read. I guess you could mix sizes front to to back as long as they are same per axle and four wheel drive
Try this link:
http://www.alloywheelworld.co.uk/page.php/tyrecalc.htmlHi Neil, thanks for the reply. Too complicated for me! But your explanation is clear and makes sense so its good enough for me!
cheers
Lindsay