What the shapes on a European fuel pump actually mean

You are standing at a pump in a country whose language you do not read, looking at a nozzle covered in small printed shapes: a circle marked E10, a square marked B7, sometimes a diamond marked LPG. None of it is decoration. It is one EU standard, built so a hire car does not get the wrong fuel by accident.

By the Refuelia Editorial Team · Reviewed 28 July 2026

The shapes are a spec, not a design choice

The symbols on nozzles, pump screens and the fuel flap of most cars sold in Europe since the late 2010s come from a single standard: EN 16942, "Fuels: identification of vehicle compatibility: graphical expression for consumer information". CEN, the European standards body, adopted it on 12 October 2016, and it became mandatory across the EU and EEA from 12 October 2018 under the Alternative Fuels Infrastructure Directive. Britain's own rollout ran slightly behind that: UK guidance points to labels appearing on pumps and nozzles by 1 September 2019, which is a year after the EU-wide deadline. That gap is worth knowing about if you assumed every European country flipped the switch on the same day. It did not, and forecourt operators in some countries were slower than others to actually fit the new stickers, standard or no standard.

The logic of the standard is simple even where the fuels are not. Petrol and other spark-ignition fuels get a circle. Diesel and other compression-ignition fuels get a square. Gaseous fuels, LPG, CNG, LNG and hydrogen, get a diamond, sometimes called a rhombus. Inside the shape sits a letter and a number that tell you the maximum proportion of a biofuel or gas component. The shape tells your eye which family of fuel it is before you have even read the text, which is the point: it works whether or not you can read the local language on the rest of the pump.

The same shapes are also meant to appear on the fuel filler flap or cap of new vehicles sold since the standard took hold, and inside the owner's manual. That placement matters because it puts the information where you actually need it, at the moment you are stood over an open tank, rather than buried in a glovebox handbook. It is worth checking your own car's flap next time you fill up. Most vehicles registered in the last decade or so will already carry a small circle with an E number on it; older cars generally will not, simply because the requirement did not exist when they were built, which is a labelling gap rather than proof the car cannot take the fuel.

Petrol: E5, E10, E85

Inside the circle, the letter is E, for ethanol, and the number is the maximum share of ethanol allowed by volume. E5 means up to 5 percent ethanol, with a cap on oxygen content by mass as well, and it was the default unleaded petrol across the UK and most of the EU before the early 2020s. E10 means up to 10 percent ethanol, and it is now the standard pump petrol in most of Europe, including Great Britain, where it replaced E5 as the default grade on 1 September 2021, with Northern Ireland following on 1 November 2022. E85 means up to 85 percent ethanol. It is a genuinely different fuel, not a stronger version of the same one: it needs an engine built or converted for it, known as flex-fuel. E85 is sold widely in France and Sweden and in smaller numbers elsewhere; industry figures from 2018 put the European station count at around 4,000, which tells you it is a minority fuel, not a mainstream option you will stumble across on a random motorway services.

Diesel: B7, B10, XTL

The square works the same way but with biodiesel. B7, up to 7 percent biodiesel by volume, has been the ordinary diesel sold across the UK and EU for years and is what most diesel cars are designed around. B10, up to 10 percent, exists in some markets but is not universally approved by every manufacturer, so it is worth checking the handbook rather than assuming. Then there is XTL, and this one is not a percentage at all. It stands for a family of synthetic paraffinic diesels, produced from biomass, waste oils, natural gas or captured carbon and hydrogen, that meet a separate standard, EN 15940, rather than being a blend with ordinary crude-derived diesel. The X in XTL covers several production routes, biomass-to-liquid, gas-to-liquid and power-to-liquid all end up under the same square label. Hydrotreated vegetable oil, HVO, made largely from used cooking oil and waste fats, is the version you are most likely to see at a pump carrying the XTL label. It behaves close enough to mineral diesel that many current diesel engines can run on it without modification, but the label is telling you it is a different production route, not a percentage of something else mixed in, so it is not directly comparable to a B10 claim on the same square.

Can your car actually take E10?

For most drivers the practical question is not the shapes, it is whether their own car is happy with the ethanol content now sitting in the standard pump. Industry figures suggest around 95 percent of petrol vehicles on the road can use E10 without any issue, and every car built since 2011 should be compatible as a baseline. The RAC puts the incompatible group at roughly 600,000 vehicles in the UK, about 3 percent of the petrol fleet, and the general rule of thumb is caution with anything registered before 2002, along with classic cars, some motorcycles and older small engines like strimmers and generators. If your car falls into that group, the standard fuel is not gone: E5 is still sold, just as the "super" or premium grade, usually 97 octane or higher, usually at a higher price, and not stocked at every station, particularly outside towns. The UK government runs an online E10 compatibility checker built from manufacturer data, but it comes with a fair warning attached: it cannot account for a car that has had its fuel system replaced or modified since it left the factory, so treat it as a starting point, not a certificate. It is also worth knowing that the switch was sold on a climate benefit, and the exact size of that benefit depends on who you ask. Fuel Industry UK describes the move to E10 as equivalent to taking up to 350,000 cars off the road, while the RAC has cited a government estimate of around 750,000 tonnes of CO2 saved per year. Those are not necessarily contradictory figures, they measure different things, but the fact that two respectable industry sources reach for different comparisons is a fair sign that the precise number is softer than the headline suggests.

Britain was not first, and the fuel was not universally welcomed elsewhere either. Germany introduced E10 back in 2011, a decade before the UK, and ran into a genuine consumer revolt: drivers avoided it at the pump even though it was consistently cheaper than the alternative, local green groups including Greenpeace pushed back on the environmental case for it, and independent testing at the time suggested the real-world fuel economy of E10 was worse than E5, which undercut the CO2 argument in the public's mind even if the tailpipe chemistry still favoured the blend. That episode is worth remembering whenever a fuel change is announced as a simple environmental upgrade: the chemistry and the politics of getting drivers to actually trust and use a new blend are two separate problems, and Germany's experience shows the second one can drag on for years after the first is settled.

What actually happens if you get it wrong

A single accidental tank of E10 in an older, non-approved car is not usually catastrophic. The RAC's advice is that you may notice poorer cold starting and rougher running, and the fix is to run the tank down and refuel correctly rather than panic. The damage risk builds with repeated, sustained use rather than one mistake. Ethanol is hygroscopic, meaning it draws in atmospheric moisture, and that moisture is what corrodes brass, copper, lead, tin and zinc components inside older fuel systems. Ethanol also acts as a mild solvent on rubber, plastic and fibreglass, which is why older hoses, seals and gaskets degrade faster than they were designed to. UK government testing cited by motoring press found exactly this pattern over time: degraded fuel hoses and seals, blocked filters, damaged fuel pumps, corroded carburettors and injectors, and corrosion inside the tank itself. None of that happens overnight, which is exactly why it catches people out: the fuel looks and pumps identically to what came before it.

What a map can and cannot tell you here

A map can tell you, reliably, which fuel grades a given station sells, because that is fixed by the pumps installed there and rarely changes without a renovation. What a map cannot tell you is whether the specific E10 or E85 nozzle at that station is actually working this morning, whether the pump is out of stock, or whether a card reader is down. That is live, physical, on-the-ground information, and it goes stale the moment it is collected unless someone updates it. This is the entire reason a driver report with a timestamp matters more than a database entry that has not been touched in six months: the fuel type is mappable, the working state of the pump right now is not, and treating the two as the same thing is how apps end up sending people to a station that technically sells what they need and practically cannot give it to them.

One country publishes the second half officially. The French government's fuel dataset carries an out-of-stock flag per grade per forecourt, so for France the question "is the E85 nozzle usable today" has a public answer rather than only a guess. Refuelia tallies it every half hour: see how many stations currently report each grade unavailable, with the time the count was taken. Everywhere else, the label on the pump is still the reliable part and the rest is somebody having looked.