You're stepping into a gray area there. Given equal loading, will the tire with a lower wear index but a higher load index last as long as a tire with a lower load index but a higher wear rating? Or should I ask; given equal loading, will the tire with a higher load index but a higher wear rating last as long as a tire with a lower wear index but a higher load index?badboyeee said:Ah! but the 205/50 Kuhmo Ecsta 711 only has a 260 treadwear rating while the 195/50 has 320. So the 195/50 will save you more than just 2 bucks in the long run since they last longer! And since when can our cars go over 130+ mph anyways?
As you help to point out, a higher speed rating index implies much more than the tire's capability to survive a specific sustained speed. Mazda supplied the P5 with V-rated tires (149mph), even though the stock P5 is incapable of reaching speeds that approach 150mph. My belief is that Mazda was well aware that the 83 load index is marginally inadequate for the application and opted for a higher speed rating tire that could better withstand the resulting elevated operating temperatures.
What I can say for certain is that my specific application, of 205/50-16 87Y tires with a treadwear rating of 220, performs MUCH better than the OEM tires.
