Even though we are starting to drift off topic, I will add comment on the latest post which helps understand why knowing how to read a DOT code is IMPORTANT.
I thought Dunlop was a UK company but they have factories in America since labor is probably the same so why worry about shipping costs. I don't know if they make ST tires, if that's what you want to put on your trailer. Other owners have such a distrust of ST tires they have made conversions to LT (light truck) tires, but in any case you must pay very close attention to the weight ratings.
Allegedly, Maxxis tires are also American made for trailers and are rated as some of the best ST tires available. Because of this they will be more expensive. You might still check the DOT code to confirm its manufacturing location, but then you'll need to bring a printout of the 900 codes for where tires are made around the world to cross reference exactly where.
Besides questional quality for trailer tires other causes are owner-based and prone to owner actions. The tires should be covered when stored to minimize sun damage from sitting so long, tires that sit too long in one spot will get flat spots from not moving, tires must be kept at proper inflation. Some owners even go through the trouble of putting their trailer on jacks at the frame to relieve pressure on the tires. Unfortunately storage is counter to how we treat our trailers since we don't use them often to keep the tire rubber supple and flexible. Then there's driving habits. I have not seen an ST (Special Trailer) tire with a speed rating higher than 65, but I have seen plenty of trailers being towed faster than that for long periods. Then of the unusual length of trailers many owners cut turns too soon and this can cause a trailer tire to go up onto a sharp curb or driveway and this cuts into the sidewall. Inflation is not checked each day and this is critical (I carry a compressor and reliable tire gauge for this on every trip).
Finally, there's the tire twisting that occurs with trailers because of the stance of the tire attached to axles that do not turn nor have a differential. Even a vehicles rear tires spin at different speeds via a "differential" on a turn to reduce wear and tear. A trailer's tires do not to this. Take note next time you are making a severe turn (forward or backward) and you will see the trailer tires no longer standing straight up and down. The tires will be positioned in wierd angles and you can only imagine the stress being put on the tire - sharper the turn the worse it is. It is very important to straighten your rig over enough distance so that the trailer tires reorient themselves prior to stopping or setting up your rig for a long time. Just drive straight forward or backward for some few feet and your trailer tires will love you for it that you don't leave them in this "stressed" position.
It has been suggested that tires be changed out every 5 years just because of the interior dry rot that occurs from tires that sit too much. This is one reason you must know how to read the DOT code. Plus all those other reasons I mentioned above that we might be doing to our tires.
