Lot's of misinformation you got there. Speed rating is the compliancy of a tire and the material to handle speed AND friction. Friction is what causes heat.. not sidewall or tire flex. M5 do not come in 19s. S03s on the M3 in 19s comes in W rating which is rated good up to 168 miles not 149. The old speed rating system with Z rated tires are tires good for 149 and up. Last time I checked you my X5 came with 18's with an H rated tire on the SPs. Take a look at the temperature rating of the tire. It will tell you a lot.. Besides, that's also a moot point since the compound of the tire caused a lot of lift also... Bottom line, back to the orginal debate.. I park my cars in your garage... it will lift whatever epoxy based paint.. guaranteed. Hence me going to composite tile. If you think that's too expensive, that's your perogative.
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Originally Posted by RealShakaZulu
A speed rating for tires is really a measure of the heat handling capabilities of the tire. As the tire rolls down the road, it flexes the sidewalls and tread to keep enough surface on the road to support the load. The flexing creates heat. The faster the flexing the more the heat. Faster flex is a result of higher speed. So higher speeds mean that the tires generate more heat. Tires have a speed rating letter index that provides information about the tire's heat handling capability. Bottom line, back to the orginal debate.. I park my cars in your garage... it will lift whatever epoxy based paint.. guaranteed.. so don't know what your point is.
M5 = ZR19
M3 = ZR18
Boxter = ZR18
X5 = WR20
Vette = ZR18
As W indicates up to 149 mph (w/o failure based on heat and load) and Z in excess of 149, a W tire reaches a operating temperature induced by load (which is greater in an SUV) and speed (as we both travel 680, I will assume we both avg in the 75-90 mph range). So unless you exceed 120 (being generous), I doubt that your tire temperature reaches a higher operating temperature and maintains it to your driveway and garage.
Pleasanton (Aug 2004)
Temperature Max Avg Min
Max Temperature 102 °F / 38 °C 87 °F / 30 °C 70 °F / 21 °C
Mean Temperature 80 °F / 26 °C 72 °F / 22 °C 64 °F / 17 °C
Min Temperature 63 °F / 17 °C 58 °F / 14 °C 54 °F / 12 °C
Brentwood (Aug 2004)
Temperature Max Avg Min
Max Temperature 111 °F / 38 °C 91 °F / 30 °C 70 °F / 21 °C
Mean Temperature 80 °F / 26 °C 72 °F / 22 °C 64 °F / 17 °C
Min Temperature 63 °F / 17 °C 58 °F / 14 °C 54 °F / 12 °C
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