This might be a good time for me to explain about OE tires - that is, tires that are put on at the vehicle assembly plant. This also includes tires that are diverted into the replacement market - common called "downstream".
I've gone into detail here:
http://www.geocities.com/barrystiretech/oetires.html
What you should get out of this is:
1) That OE tires are different than tires designed for the replacement market - in particular OE tires tend to be better for rolling resistance - and that comes by sacrificing treadwear and / or traction, especially wet traction.
2) That a given line of tires may be supplied to different vehicles and different vehicle manufacturers - and each of those tires is likely unique. Making blanket statements about a line of tires based on a small sample is frought with problems and contradictions.
3) It is the vehicle manufacturer that decides what a given tire is supposed to do. If you have a complaint about the performance of a tire, complaining to the tire manufacturer has little impact. The source of the problem is the vehicle manufacturer - who is well insulated from complaints of this type.
4) That over time, tire lines tend to evolve, and while the name remains the same, the tire could be quite different than what appears to be an otherwise identical tire. This is more true of OE tires than it is of replacement market tires.
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