An asymmetric non-directional tread 12 for a tire 10 is disclosed. The tread 12 has a plurality of ground engaging tread elements 22 separated by circumferential and lateral grooves 24,28. The net contact area in a first tread half 30 is approximately equivalent to a net contact area in a second tread half 32 although the tread stiffness in the first tread half 30 preferably is higher than in the second tread half 32. The outboard side of some circumferential grooves 24 may be tapered to buttress tread elements 22 against cornering forces.