Hi all Following my post in wheels and tyre "will these fit my 2004 clk" I am still unsure if the wheels I want will fit my clk! So I thought I would try a different approach, can anyone help me understand the numbers on the wheels? Front Wheel Size: 8.5 j x 18h2 et39 Tyre size 245/40/18 Rear Wheel Size: 9jx18h2 et 39. Tyre size: 265/35/18 So let me start with what I think I know, 8.5j 9j is the width of the wheel, corresponds with the 245/265 on the tyre. 35/45 is tyre wall size. 18 is obviously wheel size diameter. Does 39 represent the offset? And if so I assume this the distance from the inner face (where wheel meets hub) to inner rim. Having looked under my wheel arch this morning there is not a lot of room, probably less than a inch between the top of the tyre and the bottom of the suspension spring carrier. I currently have 17inch standard five spoke (look a bit like a jelly mould (ugly IMO) I am prity sure they will fit under The arch but it's the off set that worries me and I am not sure where to measure from. I would also love to know your thoughts on putting these wheels on, my biggest concern is the cost of tyre (£100 to £240) and that it may make steering and ride stiff.