There is a quality of diesel. Yes. However, just because the same trucks are lining up at a refinery does not mean they are all getting ONE fuel. They blend fuels ALL the time. One named station may be picking up 100% diesel while the other truck is recieving a blended Diesel with kerosene.
There is way more to this that a picture of 5 different trucks sitting at one tank farm. Knowing a petroleum operator would greatly help one with this knowledge. Its NOT published on the interweb GALAXY of believe everything you read on the interweb. LOL
ASTM is a target standard. Some refineries and blenders use a much higher standard.
Going off ASTM is like saying obama care is sufficent for all. No specialist needed the family practicioner can also treat your cancer.
There are also alot of waste chemicals that get blended into fuels... EXCEPT California.
Im not trying to get anyones feathers ruffled here.. specifically UNBROKEN... just trying to shed alittle light on what goes on behind the pipeline walls!! lol.. and alittle light is all im shedding... theres truck loads of CORRUPTION in this to factor in as well.
Additives to play a major role in the final grade and quality. So if the guy is picking up raw diesel... I dont want it in my tank.
BTW... Im glad the air intake is working great for you! It looks like a very nice quality piece. There is no doubt that more air intake surface filtration were a engine would normally be struggling will help. Thats just a proven physics standard.