You are right, I took a look at their map and only in Canada.
Here the link and info about it...
http://www.shell.ca/en/products-services/solutions-for-businesses/commercial-fuels/diesel-fuels.html
It is my understanding, that all oil companies add additives, anti-gel, water built up, but I think, Cetane booster are extra, like shell. I haven't tried it, but I should give it a shot at least once or once in awhile.
I dug a bit further and found, shell in US has something similar, but different name. Located in some area, such as:
Shell Diesel FiT is currently being offered at approximately 95 locations in the Seattle, Washington market. Plans for expanding this offering will be assessed at the conclusion of our market test
http://www.shell.us/motorist/shell-fuels/shell-diesel-fit.html
With continuous use, the exclusive Shell Diesel FiT formula provides the following benefits:
- Carbon Deposit Build-Up: Fuel injectors deposits can reduce combustion efficiency, which can increase fuel consumption. The exclusive Shell Diesel FiT formula protects against deposit build-up to help maintain proper injector fuel flow and spray pattern and provide designed power and performance.
- Anti-Corrosion: Use of diesel meeting minimum government quality standards can result in corrosion of vital engine parts such as the fuel pump. Shell Diesel FiT contains enhanced corrosion inhibitors to help prevent fuel system corrosion to protect your investment.
- Anti-Wear: Shell Diesel FiT is formulated to help provide additional anti-wear protection for your diesel engine exceeding minimum government quality standards to help protect your investment.
- Anti-Gelling: In severe winter conditions, diesel meeting minimum government standards can “gel” resulting in the inability to start the vehicle or reduce diesel engine performance. During winter, in select cold weather markets, Shell Diesel FiT contains anti-gelling agents for enhanced cold weather performance. Look for the "Special winterized anti-gel formula" label on the dispenser.
- Water Management: Shell Diesel FiT is specially formulated to separate water from fuel and assist in water removal from fuel storage tanks to help provide consumers with dry fuel.
- Heavy-Duty Truck Fuel Economy & CO2 Savings: Based on extensive tests, Shell Diesel FiT achieved a 1.3% mpg saving for heavy-duty trucks in long-haul service and an impressive 4.8% mpg saving for heavy duty trucks in more severe stop and go city conditions, compared to regular diesel meeting only minimum government standards.
Shell has several video, it a must see, it explains a lot.
Engine Power & Perfermance
Rust Protection
Gelling
Water Separation Dry Fuel
Fuel Economy
Anti Wear
https://www.youtube.com/watch?v=QdgWd_3SRAo