Originally Posted by bismic

That would be good but my point above is that even the OE source may not be selling them the top tier quality. Then again they might, who knows.

Originally Posted by bismic

Plastic is one of the hardest materials to evaluate the quality in. As plastic ages, they pretty much all get brittle and degrade in appearance (translucent materials become cloudy). Two materials can look identical, but have great differences in some very important characteristics and properties. My former employment was with a company that sold plastic to the automotive industry (among others). It was expensive material. Quality was normally top tier, but when it wasn't (all production lines can drift in quality as instrumentation and machinery age and wear), it was sold to the aftermarket if possible. Thermal stability was one parameter that was important. Heat, oxygen exposure, and UV light can cause degradation. There is no doubt that the lower quality material was being sold to companies that made aftermarket automotive parts. Physical appearance was not a way to distinguish between top quality and second tier quality (although when pigments were added to the material for coloring purposes, appearance was tightly controlled). The quality of the product had to be determined through analysis and measurements. I don't know what material is used in making the Dorman product. That isn't "material" in my choice, I am prejudiced against them in general. IMO success is determined in years on this type of product. I expect AT LEAST 10 years of life in stability and appearance. Usually the OEM product delivers this. As in all things, there are exceptions.

For the benefit of the 6.0L community, aftermarket products have to be tried so we can have cheaper alternatives. I just hope a large percentage of the people using aftermarket products post up their results (ie report when/if it fails AND report every 2 or 3 several years how it is doing). Doesn't matter if it is degas bottles, radiators, or hpops!