Thank you for your tips and welcoming me here.
Another question, what station do you prefer to use for diesel, how do you like Sam's club/Costco diesel?
From coast to coast, I have my favorites, but in Maryland I tend to prefer Shell. I often avoid buying fuel in Baltimore City, since I'm often up and down 97 or Rt2, and there are many competitively priced and quality stations that have better turn-over than in the city.
A decent rule to follow is to prioritize stations that go through a lot of diesel, which reduces the chances of getting fuel that sits for a long time. Personally, with some exceptions, I've found that many stations are selling the same product, often without their own additive package. Diesel tends to differ a bit from gasoline, where (with gas) there is greater variety in quality, source, options, packages, and final product.
In central Massachusetts, we used Sam's Club diesel partially because the price was so good, and mostly because they had contracted with numerous local fleets, and they had new pumps, new tanks, and went through a lot of fuel weekly. I've used the diesel at Sam's along Rt97, but not often enough to comment on results. I have not used Costco diesel, but in general, if any station is going through fuel at a high rate and has newer facilities, it's less likely to have problems.
If you want to put in the time, you can research from what source different stations/companies get their diesel. This still doesn't tell you about how well is is stored, or what they add to it, but it may help you make a more informed decision.
Also: For our MkIV's, I use PowerService DFS (white bottle) in the cold seasons, but for the Mk7, I add a little (of the same) to
every tank of fuel. A search for additives and the comparison of demulsifiers, emulsifiers, water solubilizers, etc. will provide you hundreds of pages of good reading.
Hope this helps.
