I delivered to 44 Charlotte area Shell Branded stores for 6 years and we never brought "Shell Branded V power" diesel. It was always unbranded fuel.
The Gas was "Always Branded" but not the diesel.
Cetane rating is 40 now from 42 prior to bio-diesel being blended.
The only stores here that offer Branded Diesel here with Additive are Exxon and Marathon.
Everyone else has unbranded fuel. There should be a decal (small)on the pump saying" this product is not a "XXXX branded product".
I live in RI, and they do not list cetane at the pump. Lately I've been using Mobil diesel. My average lately has been 46 mpg with winter tires on. Though I've changed my driving style significantly. In the next couple of weeks, I'll be swapping out the winter for my summer tires. Hoping to see a 20-30% increase in my mileage at that point.
As for Shell, about 4 fillups ago I had a problem. It was extremely cold that day, and the pump ran very slow. As a result, the pump never developed back pressure and ended up spilling out onto the ground. The weather played a major part of it.
I know that there are diesel winter blends to prevent gelling and other cold related issues. Is there a noticable difference between the summer and winter blends in terms of fuel economy, as with the gasoline ones?
I buy my fuel where it is the absolute cheapest. Fuel is fungible. It's exactly the same fuel everywhere. The only reason to pick one distributor over another is if you are in love with whatever marketing additive they claim to put in their fuel.
I have no particular affinity for any particular additives so I pull into the station with the cheapest price/gallon. At the moment that is the Chevron station at Van Ness Ave and Pine St in San Francisco where diesel is $4.09/gal.
CountryMark Diesel R is all I use. Its consistently 50 cetane, and widely available throughout Indiana and Illinois. Plus, its extracted and refined here, so no foreign oil issues. On TDI Club Diesel R is only bested by Amoco BP, and I'm unsure if that formulation is produced anymore.
I also add Powerservice to every tank. While cetane gain may be negligible because I'm already getting 50+, it also increases lubricity and decreases wear in my upgraded injectors.