I need to replace the aluminum wheels on my '99 Outback and am considering a larger wheel/tire. The existing wheels all leak at the bead and have kissed too many curbs! Has anyone installed larger wheels/tires? Were there any clearance problems, or problems with the ABS system? Anything I should avoid?

Just watch your offset, and understand that your speedometer might be a bit off...

 

There is a tire size calculator on a Miata site, maybe you could search and find it posted here somewhere...

http://www.miata.net/garage/tirecalc.html

Don't go for more than 16 inches, the suspension geometry isn't set up for 17-18 inches and the car will not ride or handle well. Part reason is the increased weight of the wheels, which the dampers can't cope with.

 

At 16 inches, you should have a 50mm offset. Rim width is also very important, minimum width in relation to tyre section is 70%, but this gives really soggy handling. Try to aim for 80 or above. Most 16 inch rims will be 7 inches wide, and I would stick to a 205 tyre for this rim width. Wider tyres are also more likely to rub.