Originally Posted by mbaessler
It is really hard to find the Cetane level of the different diesel brands.
That's why I gave up on this same line of inquiry last year. Data was mostly just hearsay, with the most "authoritative" data derived from a way out of date thread post on the TDI forums. Telling people to ask station attendants is a joke suggestion: last time I asked a station attendant about their diesel they didn't even know what "winterized" meant. Hell, the attendant didn't even know if it was #2 or #1.
That, and the first time I filled up at a coop outlet for a brand of "premium diesel" (Cenex Roadmaster XL) I immediately lost 5 mpg and started getting 24 mpg on the interstate. I'm guessing it was dirty fuel. For bonus irony, I had driven 10 miles out of my way to get this "premium diesel".
Anyway. Last time I stopped at a Kwik Star that was selling reputable
premium diesel (winterized) I just skipped it and put in straight #2 (i.e. non-winterized).
Furthermore, it's not the truck stops you want to avoid. They have high turnover and therefore have "fresher" 60 million year old diesel. Rather, you want to avoid any station that looks like they sell 40 gallons of diesel a year or otherwise appears poorly maintained.
All this to say: be more concerned about dirty or high-sulfur fuel than cetane levels... the minimum cetane level for highway diesel is a federal standard. If you really want to boost your cetane equivalent, I suggest buying some Diesel Kleen from Walmart and dosing your own tank up to "premium diesel" levels. I do.