E10 fuel vs E5 – Is E10 the right fuel for you?

Image of person filling up their car with E10 or E5 unleaded fuel

Passenger cars, Classic Cars and Motorcycles will all need further protection as the ethanol content in fuel rises. In this article, our technical advisor explains how E10 Fuel will affect our vehicles and what you can do to combat this.

What is E10 fuel?

E10 petrol could be in the fuel pumps from 2021, in short, the amount of ethanol in our current fuel will double from 5% to 10%. The 90% part is regular unleaded petrol and the ethanol part of the fuel is a government drive to increase the biofuel produced in terms of renewable energy from crops to reduce or at any rate try to reduce emissions.

What it does

Ethanol increases the octane rating of petrol. This is key for resisting detonation so that the fuel has a control burn rather than an explosion or pinking*. So in effect, the role of ethanol is beneficial to the efficient running and power delivery of a petrol engine.

What are the problems with E10 Fuel?

Ethanol itself is very corrosive and ethanol with moisture (that it holds) is also very corrosive to steel fuel tanks, glass fibre and certain rubber hoses and fittings. Ethanol has a lower calorific energy content than petrol. This can impact the fuel economy of a vehicle with the consumption increasing.

How can I combat its effects?

Millers Oils has developed fuel treatments to deal with the proposed E10 fuel. VSPe Power Plus tackles classic vehicles right to the birth of the automobile. EPS is for the more modern cars and motorcycles. It works by inhibiting this corrosive behaviour by joining with any free bonds on the ethanol. This effectively stops the corrosion from even starting. The fuel treatments will not affect the beneficial part of ethanol i.e. make combustion more efficient.

*Pinking – also known as ‘pre-ignition’ is caused when the temperature and compression combination within the cylinder gets high enough to cause ignition of the fuel/air mixture without the use of a spark plug.

Update – 20-02-2023

A car being filled up with E10 unleaded petrol.


E10 vs E5 unleaded 1 year later: Is it worth it?

In September 2021, E10 fuel has been readily available at fuel pumps. This replaced the standard E5 fuel with the more environmentally friendly alternative. The longer it has been available, more and more people have been asking… is it more economical? And if so, by how much? The question came about because motorists noticed they seemed to be filling up their vehicles more when using E10 compared to E5.

Should I switch back to E5?

It has been proven that E5 gets a better MPG than E10. Does this benefit outweigh the difference in price?

A driver’s MPG typically depends on a few things:

  • Driving style – Make sure you don’t accelerate or decelerate harshly.
  • Drag/Air resistance (roof racks and boxes).
  • The type of roads you drive on – Motorways mean you can keep a steadier speed, increasing MPG. Country roads will greatly reduce MPG due to different inclines and turns in the road.

In optimum driving conditions where you are able to maintain speed and have gradual acceleration with little drag affecting your car, it has been estimated you could get up to 3MPG extra using E5. This difference would make the cost per mile almost identical between the two fuels.

So really, it is entirely up to you but whichever fuel grade you choose, there are a few ways of making the most of each one.

Making the most of my fuel

Fuel prices reached record highs over the last year so every litre saved is a job well done. Below, we have put a short list of what we think are the most useful tips for getting the most MPG out of each tank.

For more tips on how you can become a fuel-saving expert, see our fuel-saving tips blog by clicking here.

What E10 Fuel additive should I use?

Using the best car maintenance products is a must if you are wanting to improve your engine’s efficiency. For example, using Millers Oilsover a budget option will have decreased friction in your engine parts, leading to better efficiency and less of a chance to cause mechanical problems happening later down the line.

The corrosion associated with E10 fuel is nothing to be ignored. Over time it may corrode the metal parts within your fuel system leading to costly repairs. Keeping on top of it not only acts as a preventative measure but will keep your vehicle’s performance at an optimal level. EPS (Ethanol Protection System) is a product we offer E10 fuel additives that helps prevent corrosion and rust within your engine and can be used as you fill up just like any other additive.

As we explained in this blog, E5 is the more expensive fuel at the pumps. If you are debating using E5, you should think about how to get the most out of it.

We listed helpful tips you can do whilst driving, but what about anything else? E10 Fuel additives are a great way to improve the efficiency of your engine and get the most out of your fuel. ECOMAX is a fuel additive that increases the MPG and power of your engine. It does this by raising the cetane levels of the fuel in your car! It also acts as a detergent for your engine, which promotes cleanliness in your fuel system.

To buy these products, find a stockist near you by clicking here.