Posted by David on August 20, 1999 at 06:27:22:
In Reply to: Re: Tire Size posted by Roger on August 19, 1999 at 17:32:07:
You are correct regarding Tire & Rim Assoc. guidlines for specifics. I was was speaking more in generalities, form one aspect due the technical nature of the topic and the other due to the global market influence. Your response indicates you are or have been involved in the industry, with a high level of knowledge. So I am sure you know where I am going.
Although Tire & Rim is the governing body for domestic giudlines, the influence is great from the outside. We have ETRTO and JAPMA to contend with as well. These are the European and Asian governing bodies. Agian - in generalities, T&RA accepts both of these associations standards while they do not completely accept T&RA's. There are many levels and issues involved and there is distinct seperation by product segment, PCR, PCR performance, LTR and MRT/MTR/TBR. Those issues include but are not limited to, global use of a single product, production location (outside the US), and technical orientation(or guidance) due to rubber manufacturer ownership. With true ownership and majority %age domestic technical guidance comming from only two companies(loosley), Goodyear & Cooper, this is a reality. Raw material related production costs on the manufacturing side do factor into the equation as well. At this time the is no one international, completly controlling, governing body. So it is very hard to answer your question with one answer or formula.
Given your original question was based on a passenger car tire, the segment where the largest conflicts exist due to that segment being the largest on a global scale, you are best served understanding that there can be measurable dimensional differences from one tire to the next in the same size when comparing manufacturer(brand) to manufacturer(brand) as well as within a single manufacturer(brand) from one style, model or type of tire to another.