E5 vs E10: Which Is the New Fuel?

In most countries that have updated petrol standards, E10 (petrol with up to 10% ethanol) is the new default grade, while E5 (up to 5% ethanol) typically remains available as a premium or “protection” fuel. Availability still varies by country and retailer, so always check the pump label where you fill up.

What E5 and E10 Mean

E5 and E10 are designations for petrol that signal the maximum percentage of ethanol blended into the fuel. E5 contains up to 5% ethanol; E10 contains up to 10% ethanol. Ethanol is a bio-component that can reduce lifecycle greenhouse-gas emissions compared with pure fossil petrol, but it has slightly lower energy content than gasoline, which can reduce fuel economy by roughly 1–3% when moving from E5 to E10 under typical driving conditions.

Where E10 Is Now the Standard

Many markets have adopted E10 as the main 95‑octane (regular) petrol to cut emissions and align with renewable-fuel mandates. The following examples illustrate how the transition has unfolded:

• United Kingdom: E10 became the standard 95 RON petrol in Great Britain in September 2021 and in Northern Ireland in late 2022; E5 remains widely available as 97+ RON premium (“super”).
• Ireland: Switched regular unleaded to E10 in 2024; E5 continues as premium grade.
• European Union: Many countries (including France, Germany, the Netherlands, Belgium, Finland, Sweden, Denmark, and others) have E10 as the common 95 RON grade; E5 often remains as premium. Some southern markets still offer E5 widely, so labels matter.
• United States: E10 has been the de facto standard gasoline for years; E15 is available in many areas for 2001+ vehicles, while E0 (ethanol‑free) is sold in limited markets.
• Canada: E10 is common nationally, with higher blends in some provinces depending on local mandates.
• Australia: E10 is widely available and may be the main regular grade in several states, though E5/E0 can still be found depending on retailer and region.

Because policy and retailer offerings vary, the label at the pump is the definitive guide to what you are buying in your area, even within the same country.

UK and Ireland at a Glance

In both the UK and Ireland, the “new” regular petrol is E10. E5 remains primarily as 97–99 RON premium for drivers of older or specialty vehicles that require it. Pumps are labeled clearly with “E10” or “E5” inside a circular symbol.

EU Snapshot

Under EU labelling rules (EN 16942), pumps show “E5” or “E10” in a circle. In much of northern and western Europe, E10 is the standard 95 RON; E5 persists as premium. Parts of southern Europe still rely more on E5 for regular unleaded, but E10 availability has been expanding.

North America

The U.S. overwhelmingly sells E10 as standard; E15 is increasingly common for compatible vehicles. Canada broadly uses E10, with specifics set by provincial mandates and supplier choices.

Will Your Vehicle Run on E10?

Most modern petrol vehicles are compatible with E10, especially models built since the early 2000s. However, a minority—particularly older or specialty engines—may require E5 or ethanol‑free fuel to avoid drivability or material‑compatibility issues.

• Generally compatible: Most petrol cars and light vans from the early 2000s onward; the vast majority of vehicles sold in the last decade are designed for E10.
• Use caution or avoid E10: Classic and vintage cars; some pre‑2011 motorcycles and scooters; certain older direct‑injection or carbureted engines; small engines (lawn/garden tools), marine engines, and other equipment not rated for ethanol blends.
• Symptoms of incompatibility: Perished fuel hoses/seals, rough running after switch, hot‑start issues, or fuel‑system corrosion—especially in rarely used or long‑stored vehicles/equipment.

If your manufacturer does not approve E10 for your model/year, stick with E5 premium or ethanol‑free petrol where available. When in doubt, check official guidance.

How to Check Your Compatibility

You can confirm whether your car, bike, or equipment is E10‑ready by following a few simple steps.

1. Consult the owner’s manual or the fuel‑cap label for ethanol blend approvals (e.g., E10, E15).
2. Use your government’s or manufacturer’s online compatibility checker for your exact make/model/year.
3. Ask a franchised dealer or the manufacturer’s customer service if documentation is unclear.
4. For small engines, check the equipment manual; many specify a maximum of E10 or advise using E5/E0.
5. If the vehicle has modifications (aftermarket fuel systems, classic restorations), seek advice from a qualified specialist.

Taking these steps helps prevent avoidable issues and ensures you choose the fuel your vehicle or equipment is designed to use.

Fuel Economy, Emissions, and Performance

Switching from E5 to E10 typically results in a small drop in miles per gallon due to ethanol’s lower energy density, often around 1–3% under normal driving. In exchange, E10 can lower lifecycle CO2 emissions compared with pure fossil petrol, depending on the ethanol’s source and production pathway. Most drivers notice no performance difference; high‑performance engines should follow manufacturer octane and ethanol recommendations.

Pump Labels and What to Look For

Across Europe and many other markets, pumps carry standardized signage. Look for a green or black circular label with “E5” or “E10.” Octane (e.g., 95, 97/98/99 RON) is shown separately on the grade selector. In North America, labels typically state “Contains up to 10% ethanol” (E10) or list E15 explicitly; octane is shown as AKI (e.g., 87/89/91).

Storage, Seasonality, and Small Engines

If you store fuel or run engines infrequently, ethanol content matters because ethanol is hygroscopic (it attracts moisture). This can be more pronounced with E10 than E5.

• Keep fuel fresh: Buy only what you’ll use in 1–2 months; use stabilizer products where recommended.
• For seasonal equipment: Many makers recommend E5 premium or ethanol‑free fuel to minimize storage issues.
• Marine and off‑grid use: Follow manufacturer guidance; water contamination risks are higher in humid environments.

These precautions reduce the risk of phase separation, corrosion, and hard‑starting after storage—issues more commonly reported with higher ethanol blends in seldom‑used engines.

Bottom Line

The “new” fuel in many countries is E10 for regular unleaded, chosen to help cut emissions. E5 remains available—often as a higher‑octane premium—for vehicles that need or prefer it. Always follow your vehicle’s specifications and read the pump label before filling up.

Summary

E10 has become the standard petrol grade in numerous markets (including the UK, Ireland, much of the EU, and North America), while E5 persists as a premium or protection grade. Most modern petrol vehicles are E10‑compatible, though older cars, some motorcycles, and many small engines may require E5 or ethanol‑free fuel. Expect a small fuel‑economy dip with E10, but potential emissions benefits. When uncertain, check your owner’s manual, official compatibility tools, and the pump label at your local station.