I have 18 b 8 on front, and 18 b 9 on rear. The front tyres are 235 40, and the rear 265 35. The fronts are fine, but the back stick out a little way. The rear gaurd needds to be pumped a little for the wheel/tire to fit in properly. I have scrubage on the front from the inner wheel arch cover, and the rear from pot holes etc.. I was going to fit 19inch wheels on, but, with the 18's.. i really dont think 19's would fit!