Load Index...

[LEB Ben]

Again...out of my element, just trying to get an understanding of the passenger car load index rating. I understand sidewall rating for truck tires, ie c vs. e, in which case load amount usually correlates to wear amount and the stouter tire usually wears better, although a rougher ride. Now when it comes to passenger tires, in particular a 94 vs. a 96 rating (both are V rated rubber compunds)...is there enough of a difference in side wall support and tire construction to extend the life of the tire??? Or do passenger car tires not translate as such??? In my never ending world of cheapassness, I'm trying to determine if the extra $48/tire (same brand and series of tire) will be worth it in tire life or if results would be negligible.

 

[fatherdoug]

Is the 100 pound difference in load carrying capacity (94 vs 96) worth the extra $48 per tire? If I read the charts correctly, the speed rating is also tied into the load index. An "S" rating will allow you to carry 1456 lbs(94) per tire at a maximum speed of 112 mph.

 

[LEB Ben]

That's what I'm wondering...does the extra reinforcement to handle the extra 100lbs make a difference??? I'd imagine an 88(?) to a 96 would make a difference, but to me it looks like load ratings are pretty tightly packed and wear characteristics would be negligible at best. Just wanted to make sure.

As for the speed rating...it is included in the load index, but seems to be an independent rating based on rubber compound...ie a V will be slightly harder than a W and a W harder than a Y etc etc. So you can have a 94V and a 94W in the same brand and series of tire, so the load is the same, but the tire is rated for different speeds. Which in turn, the softer compound yields lower rated expected wear time. At least that's my take.


All that said...I think I'm gonna go with the 94V Bridgestone Serenity Plus' in a 215/55/17 on the Lincoln. They're about a .5" taller than stock and a .5" narrower than stock. Compound is rated the same as stock, but it's bumped one speed rating up from OEM. It's also rated as a 75k tire as opposed to a 60k tire like OEM. This is a brand new tire to the market as of June 10th...but is supposed to eliminate most if not all of the complaints surrounding an LRR tire. The tire is supposed to do waaaaaaay better in wet driving conditions (pavement and hydroplaning) and feel more stable than current LRR tires. It was tested head to head with the Michelin MXH4 (?)...the big daddy of LRR's, and outperformed across the board.

 

[Truckin4life]

Calculate how many miles your buying per dollar. From manufacturer specs. Then see how many more miles 48 should buy. If you think it's reasonable go for it. I doubt it will be though.