75mph ST tire

The standards for choosing an appropriate tire are located in the FMVSS. Well I should say minimum standards.

FMVSS 109

and

FMVSS 119

This whole discussion makes me think also of how a manufacturer, either the tire company, or the vehicle ( or trailer ) might consider what tire is appropriate. For instance, many if not most 150 series "light trucks" come from the factory fitted with "P" tires. At first glance a person might think that doesn't sound right....P is for passenger, I bought a truck, so why does it have those tires ? But obviously, they are a correct fitment when used within their load limits.

Perhaps I need to step in here to clarify some items:

First, read my write up on Tire Standardizing Organizations: Barry's Tire Tech - Tire Standardizing Organizations

Then understand that the US Federal government ACCEPTS those standards, but doesn't REQUIRE a tire comply with those standards. It does require the tire to comply with certain marking and testing regulations, but a tire manufacturer is not obligated to follow those standards - although why anyone wouldn't is beyond me.

The Kumho Radial 857 is a tire line designed to ETRTO standards and for use on utility vehicles commonly used in Europe, but rare in the US. The VW EuroVan and the Ford Transit are probably the only vehicles that the US folks would be familiar with. These vehicles are smaller than what is commonly used in the US for the same purpose.

The line carries the "C" designation (for Commercial), which is printed AFTER the tire size. This an ETRTO designation.

Because of that, the US arm of Kumho obviously sees this line of tires as having only usage on trailers - as the vehicles this line fits on basically don't exist in the US - and only lists 3 sizes, all 14".

Some LT tires CAN be used on trailers, but some are just not suitable - BUT - ST's are specifically designated by the US tire standardizing organization, The Tire and Rim Association, as trailer tires. That's what the letters ST mean - Special Trailer. This designation is a US only designation. It does not appear in ETRTO, nor JATMA yearbooks.

But be very careful interpreting what is published by the tire manufacturers. The wording becomes very important. For example, if a tire manufacturer is asked if an LT tire can be used in place of an ST tire, the answer will be "no" - because an LT tire of the same size will have a lower published load carrying capacity. No tire manufacturer will want to be in the position to defend that in a court of law.

However, if you ask if an LT tire is suitable for use on a trailer, the answer might be "Yes" - as the question asker hasn't defined the loading and there are situations where an LT can be used on a trailer. Just be aware that the tire manufacturer might not agree that their LT tires SHOULD be used on trailers - and say "No".

RinconVTR wrote:

westend wrote:
The tire designation letters are mandated by the US DOT. It's as American as you can get.

Mandated? For imports? Oh, ok.

Let me get this right...you say our government DIRECTS the OEM's what to etch in their mold tools, what you see on your tires?

As an OEM engineer for a large manufacture of product customers demand (many!) third party certifications...I highly disagree. Sir.

I'm saying a tire mfg. can't just pick out the designation on the sidewall because the DOT requires the tires to be tested and marked correctly. This is in order to be sold and used in the USA. AFAIK, most tires are imported from country of mfg.

If you are an engineer, this should all be understandable.

RinconVTR wrote:


No sir. YOU look again. Light trucks, vans and transporters are listed under "special feature". That doesn't make anyone suspect eh? Come on now...get back to reality.

Do you believe the marketing hype or not? Which is it?

Cant have it BOTH ways silly wabbit...twicks are for kids.

Ok, so let me get this right Rincon....you say that "it ain't so" because it's listed under "special features".

I just went to the Kumho USA site, and looked at the descriptions of five different random tires in their lineup. In every single one of those descriptions, they list "special features" for that tire.
Perhaps you should take this discussion up with the marketing folks that take care of this for Kumho. Because by your standards, they sure are saying a lot of stuff that just ain't so.

westend wrote:
The tire designation letters are mandated by the US DOT. It's as American as you can get.

Mandated? For imports? Oh, ok.

Let me get this right...you say our government DIRECTS the OEM's what to etch in their mold tools, what you see on your tires?

As an OEM engineer for a large manufacture of product customers demand (many!) third party certifications...I highly disagree. Sir.

The tire designation letters are mandated by the US DOT. It's as American as you can get.

Huntindog wrote:
No excuses needed. You need to read it again.

I will help you:
If we look on the kumho usa site, we see they call it a tire "for light trucks, vans and transporters"....but here in north america, they also call it a "trailer tire".

No sir. YOU look again. Light trucks, vans and transporters are listed under "special feature". That doesn't make anyone suspect eh? Come on now...get back to reality.

Do you believe the marketing hype or not? Which is it?

Cant have it BOTH ways silly wabbit...twicks are for kids.

The Kumho 857's mounted on my trailer have the following molded into the rubber of the side wall: LT Radial

EDIT: Many consumers understand there are a myriad of products that are sold on various global markets. Build the item to meet the applicable standards and needs of different markets, and make more money. What a concept.