If anyone is from the UK and can help me confirm:
It seems like fuel types are mostly referred to by descriptive name, like "Diesel", "Unleaded", "Premium Unleaded" rather than their blend codes like "B7", "E10", "E5".
I think I should be using the longer name where possible around the app, but would the codes be understood when short on space (like on a map pin)?
@zachsimone From the UK here. I've never heard people refer to the fuel by the ethanol content.
The most common way of referring to fuel by car drivers is just “Diesel" or the RON number (95, 98, etc) of unleaded. If you just put the cheapest fuel in your unleaded car and/or you don't care, you’ll likely just say "Unleaded".
Fuel stations will tend to put their branding on the price board, which is usually "Regular", "Super”, etc. I don't often hear people say those, since they vary by brand.