What is E10 petrol: A Complete Guide

E10 petrol replaced E5 as the standard petrol grade in the UK in September 2021. This blog post aims to clarify what E10 petrol is, its benefits and how it compares to its predecessor, E5 petrol. We’ll also delve into which vehicles are compatible with E10, and how it relates to unleaded petrol and the standard 95-octane fuel.

What is E10 Petrol?

E10 petrol is a biofuel made by blending petrol with up to 10% ethanol, a renewable energy source derived from plant materials such as crops and waste wood. This blend aims to reduce the overall carbon emissions from vehicles, making it a more environmentally friendly option compared to its predecessors. The introduction of E10 petrol is part of the UK’s commitment to lowering greenhouse gas emissions and combating climate change.

E10 offers several benefits including:

Lower Carbon Emissions: Using ethanol, a renewable energy source, E10 petrol reduces the amount of fossil fuels needed, lowering each vehicle’s carbon footprint.

High Octane Rating: Ethanol has a higher octane rating than petrol, which can lead to improved engine performance and efficiency. The use of E10 fuel can help reduce engine knocking and potentially provide a smoother driving experience for motorists.

Sustainable Fuel: Ethanol is made from plant materials, such as crops and agricultural waste, which are renewable resources. This makes E10 a more sustainable option compared to petrol alone, which relies entirely on finite fossil fuels.

Should I be using E5 or E10 petrol?

The transition to E10 petrol has brought up questions about whether motorists should stick with E5 or switch to the new fuel. E5 petrol contains up to 5% ethanol, and while it’s been the standard for many years, E10’s higher ethanol content makes it a greener option. If your vehicle is compatible with E10 (which most cars manufactured since the late 2010s are), it’s recommended to use E10 for its environmental benefits. However, some older vehicles might only be able to use E5 without risking damage to the fuel system.

Which cars cannot use E10 petrol?

Not all vehicles can run on E10 petrol without experiencing potential issues. Generally, cars and motorcycles produced before 2002 are not advised to use E10 fuel. The higher ethanol content can be corrosive to rubber and certain metals used in older fuel systems, leading to damage over time. Vehicle owners should consult their vehicle’s manual or the manufacturer to confirm if E10 is suitable for their car. Additionally, the UK government provides an online checker where drivers can verify if their vehicle is E10 compatible.

The vast majority of cars, motorcycles, and other petrol vehicles manufactured since around 2000-2005 are designed to be compatible with E10 fuel. Most vehicles have information about fuel compatibility near the fuel filler cap. You can check if your vehicle is compatible with E10 petrol on this government website. If you’re car is not listed on this directory then the advice is that “owners of vehicles not listed in the vehicle checker should continue to use E5 (97+ octane) petrol, which will remain available in the ‘super’ grade.”

What happens if I put E10 petrol in an old car?

Older vehicles and classics, especially those produced before 2000, may not be compatible with E10 petrol. The higher ethanol content in E10 can cause issues with rubber seals, gaskets, and other components in the fuel system of older vehicles, leading to leaks or other malfunctions.

If you’ve used E10 in an older car as a one-time mistake – don’t worry too much! It’s unlikely to cause significant immediate damage. Modern petrol engines, can often tolerate a single tank of E10 without noticeable issues, especially if the vehicle is not used aggressively during this period. If you realise the mistake early, topping up the tank with the correct type of fuel (e.g., E5 or another appropriate petrol for the vehicle) can help dilute the ethanol content in the tank, potentially minimising any adverse effects.

Pay attention to any immediate changes in your vehicle’s performance when you use E10 – especially for a prolonged period, including starting difficulties, idling problems, or unexpected noises. For example, higher ethanol content in petrol can make it harder to turn over an engine from cold. Seek professional advice if you notice any problems.

Is E10 the same as unleaded?

E10 petrol is a type of unleaded petrol. The term “unleaded” refers to petrol that does not contain lead, a toxic substance once used in petrol to improve engine performance but later banned due to its environmental and health risks. E10 and other types of unleaded petrol, such as E5, differ primarily in their ethanol content.

Is E10 fuel the same as 95?

E10 fuel typically has a similar octane rating to the standard 95-octane unleaded petrol, known as ’95’. The octane rating measures a fuel’s ability to resist ‘knocking’ or ‘pinging’ during combustion, caused by the air/fuel mixture detonating prematurely in the engine. E10 and 95 unleaded petrol are designed to meet the needs of engines requiring up to a 95-octane rating. However, the main distinction lies in E10’s higher ethanol content, which contributes to slightly lower energy content per litre compared to pure unleaded petrol.

Does E10 fuel give lower MPG?

E10 fuel, which blends 90% petrol with 10% ethanol, does result in lower miles per gallon (MPG) than pure gasoline or E5 fuel. This decreased fuel efficiency is attributed to ethanol’s lower energy content compared to petrol. Ethanol has about 33% less energy content than petrol, which means that engines running on E10 can experience a slight reduction in fuel efficiency. This reduction in MPG can vary depending on the vehicle and driving conditions but is typically in the range of 1-3%. However, for most drivers, the difference in fuel economy is relatively small and may not be noticeable in day-to-day driving.

Marketing at ClickMechanic

Louanne is a marketing and communications professional in the automotive tech industry currently at ClickMechanic, boasting over 5 years of experience.

Louanne’s work at ClickMechanic might revolve around branding and customer engagement, but her passions extend far beyond the marketing sphere. A true foodie at heart, she loves exploring diverse cuisines and talking about her culinary adventures across the world. Her writing prowess shines through in her car-related blog content, where she offers invaluable driving tips and practical car repair advice.

In her Suzuki Jimny 4-wheel drive, Louanne combines her sense of adventure with her automotive know-how, transforming every drive into a lesson and a pleasure.