Here in the southeastern USA I try to find Wilco-Hess truck stops to buy my fuel. The Cetane rating on the pumps is always "min. 45" and is normally cheaper per gallon than other stops. Most other stations have "min. 40" Cetane posted on their pumps. I can tell a difference in fuel mpg and pulling power when I run the 45 Cetane vs. 40 Cetane. Just adding my two cents of worthless knowledge.

 

if you see fuel being delivered pass on that station, it will stir up the trash in the tanks in the ground.. wait til the next day or use another station.

 

Personally, I've stuck with the bigger brands, either Shell or Chevron, and had no issues. I did get one batch of Valero when I tried to save a few pennies and regreted it with a marathon regen. That was the first and last time..

Here are cetane values of different brands of fuel. I snagged this list from an old BMW post some time back... Forgot where exactly. I'm not sure if price varies with cetane levels.
If I'm not mistaken, the user manual for our trucks explicitly state cetane of 50 or better is recommended.

Love's 40
Pilot 40
Valero 40
Sheetz 40
Flying J 40
Holiday Stations 40-43
HESS 40-45
Husky 40-45
BP 40-42,47
Exxon/Mobile 43-46
Sunoco Gold 45-50
Shell 46
Sinclair 46
PetroCanada 47-51
ConocoPhillips through the 76 stations (California) 47-53
Chevron 49-51
BP (Amoco branded) 51

 

Just went to flmowners.com and checked the manuals and the last publication that mentioned cetane and it stated 45 for the 6.4l.
I just had to make an emergency trip to Kansas City, MO, the 2nd in 3 weeks, and filling up at 1 FlyingJ/Pilot, the mileage and the clatter was unusually loud on both trips. I used Diesel Kleen but it was still rather loud clatter especially when we slowed for the Toll Boths on the Turnpike. I did a fill in Denton, Tx, had a 30 mph head wind, at a Walmart/Murphy, and about 20 miles down the road, we had to slow for traffic in Ft. Worth, very little clatter and I did not add Diesel Kleen. So after these 2 trips, as we travel this quite often, I am reconsidering my fuel stops.

 

I usually get Exxon fuel, but I just did a 1,700 mile return trip hauling a few thousand pounds of stuff in the truck and a trailer probably at 4k or so and mostly fueling at Pilot or Flying J stations and I didn't really notice any change in MPG from what was expected with the load, nor were regens more frequent, ~500mi intervals or so. I do add the Ford fuel conditioner on every fueling, the anti-gel version for this trip in cold states.