Tier 3, Tier 4, etc. use different methods, controls, to effect end results for emissions standards for diesel engines. Tier 3 not as much as interim Tier 4, and Tier 4 final requirements. Diesel injector nozzles are very fine tuned at the factory before release to the consumer. Most manufacturers build them in clean rooms that are extremely dust/particulate free.
When fuel that has larger than normal particles of diesel try to pass through the injector it can jam the injector, cause pee like spray patterns or worse. This results in unburned fuel and less than ideal combustion. This results in smoking, poor fuel economy, etc.
Winterized or 'cut' diesel fuel in the Northeast states usually has Kero added to make it flow better, and to keep it from freezing in the diesel filters that may have trapped water in them from extracting same from the tank's condensation.
We used to use Red Line Diesel fuel catalyst for ALL our diesel foreign autos when I had my shop. Often the cars would come to the shop from having been on the mountain(s) overnight and they would be dead. Drained batteries, block heaters that couldn't overcome the effects of frozen fuel, etc. We'd take them into my shop and raise them on the lift and drain the oil and filter and fuel filter and fill the fuel tank with 'cut' diesel and Red Line. After several hours thawing out we'd send them on their way, with a big bill, and instructions on how to survive in the mountains of Vermont. These were mostly vacationers or tourists, but they all learned it takes more than a Mercedes to get through the winter here.
