Piston Slap: An “Occasional Jaunt” on…Winter Tires?

Anonymous writes: Sajeev, Recently I picked up a set of Bridgestone Blizzak WS60 winter tires for my 2006 Mitsubishi Evolution IX GSR (lightly modded at approximately 350 whp/320 wtq) and unfortunately I was unable to get a "V" speed rating in winter tires as they only came in "H". http://www.bridgestonetire.com/productdetails/TireSubBrand/Blizzak_LM-60 How dead-set are those tire ratings?  I wonder because there was an "incident" involving myself, another Evo and a BMW 135i which included speeds in excess of the 130mph speed rating (surface conditions were dry, closed road, no spectators).  Would an occasional jaunt above the speed rating of the tire cause long-term damage to the tire, or would it take a constant load to delaminate from the rim? Thank you in advance for your time. Sajeev answers: Being an H-town boy who only enjoys visiting cold climates for business or vacation gives me pause on my answer.  And while there's street racing aplenty over here, we don't try to find ourselves in jail on the wings of flying winter tires.  So with that in mind… Your question has too many conditionals and vague language (for good reason, I assume) to give a solid answer.  As such, here's a crappy answer: a tire's performance deteriorates over time, as rubber naturally hardens, stress cracks, etc.  A 1-2 year old tire might be fine running up to its speed rating, in theory. Temperature also comes into play: if you live in 100+ degree weather and want to drive triple digits for sustained periods, your tires will go much sooner than someone doing the same at 60 degrees. Duration is a big concern, as you mentioned.  There's a good chance you can run Blizzaks at or above their speed rating for less than a minute with no problem. If you ran it for 10 minutes or longer?  That "good chance" turns into a "not bloody likely" in my opinion. This notion is described in far better detail on the eng-tips.com forum. Perhaps it goes without saying, but this behavior is pretty stupid.  And since many of us are guilty of this automotive sin, we shouldn't be proud of doing it…even if damn near everyone with a lead foot and a 250+ hp vehicle has tried it at some point in their lives.  I'm not here to judge, just to speak my mind. Best of luck. Send your queries to sajeev@thetruthaboutcars.com . Spare no details and ask for a speedy resolution if you're in a hurry. from The Truth About Cars http://www.thetruthaboutcars.com

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