My 93 rolla's got a tear in the front right tire, its still holding air but I think its bulged because I could hear it when I was driving thumping a bit at low speeds, just something I dont need trouble with. But my question is should I just replace two front tires or go and replace them all??? The tread on all the tires are in good shape, but I'm not sure what I should do? I would really appreciate some help on this, I need to get it taken care of asap.