Are my Asymmetric Tires Running Backwards?

Sumitomo HTR Z3 asymmetrical tread pattern It's very common for a customer to get very excited over the tread pattern of their newly purchased asymmetric tires. While I agree the look of the grooves would lead you to have them pointing in a downward direction during rotation, the reality is there isn't a significant enough of difference for it to matter.

With an asymmetric design you need the larger shoulder block on the outside to take the abuse during cornering, this is more important than the direction of the groove on the inboard shoulder for water evacuation. The groove channels are small enough that the water will escape to the circumferential grooves when under speed. There's an unbelievable amount of force being exerted on the tire when the leading edge hits the road. Water is going to move through those lateral grooves out to the circumferential grooves for evacuation due to the force being exerted. Those grooves must also have an angle to them. While they would work just as well if they were perpendicular to the larger circumferential grooves, the tire would be very loud. By introducing an angle, noise levels are lowered. 


Testing data and feedback on the tire is based on them mounted with the outside marking facing outside. The tire will perform as intended when installed in this manner. There's no left side and right design available. The fact remains, the engineers designing these tires are achieving the performance goals with this design. You'll see this on tires from all brands using an asymmetric approach.


Listed below are some of the more popular and highly rated tires with an asymmetric design.

Michelin Pilot Super Sport
Michelin Pilot Super Sport
Pirelli PZero Nero All Season
Pirelli P Zero Nero All Season
Bridgestone Turanza Serenity
Bridgestone Turanza Serenity

For more information on a tire's asymmetric design, read "Tire Tread Patterns."


Friday, September 27, 2013 by tony rubino

I bought some pirelli p zero nero gt tires for my rx8 why is the tread pattern facing in one direction on the left side of the car and the opposit direction on the other
Thursday, July 3, 2014 by Craig Iwaishi

I just got a set of Michelin PS2's installed on my 2007 Porsche Carrera 4S - 305/30ZR19 rear, 235/35ZR19 fronts. Are these directional? I noticed that there is no left or right side - only outside. The two rears are identical as well as the two fronts.
Wednesday, July 9, 2014 by hunter

Hi Craig,
The Outside marking would indicate an asymmetric tread pattern.

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