"all cars made in Germany had to have biodegradable plastics for all plastic parts. It worked out fine everywhere else, except in the engine compartment where the heat caused the wiring insulation to break down."
Bill, why it's only happened to the plastic content in engine compartment? Am not an automobile engineer, but assume that engine is the most hottest part in a car. I my car I found that radiator and nearby areas are the hottest places.
The main reason they used it was the colonial legacy. They had plantations in southeast Asia from colonial times and still used them. Henry Ford, in the late 1920s through the mid-1940s had rubber plantations in Brazil because the plantations in southeast Asia were closed.
I have a 2003 Ford F350 with 24,500 miles (I don't drive it much). Several times a year, I have to hunt down and repair/replace wires that were chewed through by rodents. Talking to my mechanic who had just finished replacing the HP fuel pump, he explained that the insulation used by Ford in that era was regarded by the critters as strawberry short cake. Now when it's not driven, it has several baited traps under the hood. So far they like peanut butter better than the insulation.
Bill, I grew up with small British sports cars (MG, Austin Healey, Triumph). We often had problems with hoses and seals (among many other problems). It turns out that the British were still using natural rubber and that it did not hold up as well as synthetic rubber.
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