Is E10 bad for my car?

E10 is safe for most cars built after 2005. Manufacturers design modern engines and fuel systems to handle up to 10% ethanol without issues. However, some older vehicles, small engines (lawnmowers, chainsaws), and certain European cars may not be compatible. Always check your owner's manual or the manufacturer's website before switching to E10.

How much cheaper is E10 compared to Unleaded 91?

E10 is typically 3-5 cents per litre cheaper than Unleaded 91 in Australia. On a 50-litre fill-up, that's a saving of $1.50-2.50. However, E10 has about 3% less energy content, which means slightly lower fuel economy. For most drivers, the price saving still outweighs the reduced efficiency, resulting in a net saving of around $50-80 per year.

Does E10 reduce engine performance?

For everyday driving, you're unlikely to notice any difference in performance between E10 and Unleaded 91. The 3% reduction in energy content translates to a very small decrease in fuel economy — roughly 1-2 km less range per tank. High-performance or turbocharged engines that require 95 or 98 octane should not use E10 as a substitute.

E10 vs Unleaded 91: Which Should You Use?

At the pump, E10 always looks tempting — it's the cheapest option on the board. But is the saving real, or does lower fuel economy cancel it out? This guide explains exactly what E10 is, whether your car can use it, and whether switching from Unleaded 91 actually saves you money.

What Is E10?

E10 is a blend of 90% unleaded petrol and 10% ethanol. Ethanol is a renewable fuel made from sugarcane or grain crops. The "E" stands for ethanol and the "10" refers to the percentage. E10 has an octane rating of 94 — slightly higher than Unleaded 91 — but contains about 3% less energy per litre due to ethanol's lower energy density.

In Australia, E10 has been widely available since the mid-2000s. The NSW Government has actively promoted E10 adoption, and most major fuel retailers stock it at stations across Sydney, Brisbane, and other capital cities. In the UK and New Zealand, E10 became the standard unleaded grade in 2021 and 2024 respectively, replacing the old 91 octane as the default pump option.

Price Difference: Is E10 Actually Cheaper?

E10 is typically 3-5 cents per litre cheaper than Unleaded 91 at the pump. On a 50-litre fill-up, that's $1.50-2.50 less. However, because E10 contains less energy, your car will use slightly more of it to travel the same distance — roughly 3% more. So the real saving is closer to 1-2% rather than the 3-5% headline price difference.

For a driver using 40 litres per week, the annual saving works out to around $50-80 depending on local pricing. Use Benzio to compare E10 and Unleaded 91 prices at stations near you and see the current gap in your area.

Is Your Car Compatible with E10?

The vast majority of cars built after 2005 are fully compatible with E10. This includes most Toyota, Mazda, Hyundai, Ford, Holden, and Honda models. However, some vehicles are not designed for ethanol blends:

Cars manufactured before 2000 — rubber seals and fuel lines may degrade
Some European models (particularly older BMW, Mercedes, and Volkswagen vehicles)
Small engines — lawnmowers, outboard motors, chainsaws, and generators
High-performance cars that require 95 or 98 octane

If you're unsure, check your owner's manual, look for a sticker inside the fuel filler cap, or search your manufacturer's compatibility list online. Using E10 in an incompatible engine can cause rough running, fuel system corrosion, and long-term damage.

The Environmental Angle

E10 produces slightly lower carbon emissions at the tailpipe compared to straight unleaded, because ethanol is a renewable fuel. The Australian Government estimates E10 reduces greenhouse gas emissions by about 3% compared to Unleaded 91. While this is a modest improvement, it adds up across millions of vehicles. In the UK, the switch to E10 as the default grade was projected to cut transport CO2 emissions by 750,000 tonnes per year — the equivalent of taking 350,000 cars off the road.

The Verdict: Should You Switch?

If your car is compatible, E10 is a sensible choice. The price saving is modest but real, and you're making a slightly greener choice. For most drivers in Melbourne, London, or Auckland, E10 is the default and works perfectly well. Just don't use it in a car that requires premium fuel — check your manual, and use Benzio to find the best E10 prices when you fill up.