New E10 Petrol could reduce greenhouse gas exhaust emissions but delivery worse fuel economy

Fuel for thought

E10 contains 10% bio-ethanol, compared to the 5% in unleaded. This change influences a few percent decrease in greenhouse gas emissions improving overall cleanliness of cars on the road. Multiply the few percent per car and a roll-out across the nation would result in a significant reduction in the emissions of road cars helping to meet the green targets currently being set by primary London authorities.

Can my car use E10 fuel? 

Based on current EU regulations all new cars sold in the European Union from 2011 must be able to run on E10 petrol. However, this leaves around a million UK cars that would not be suitable, and this would need to be promoted to ensure people do not improperly fuel their car. Although E10 and E5 may look the same E10’s higher bioethanol content can dislodge deposits in older engines and fuel systems, causing blockages, and it can also cause some seals, gaskets, metals and plastics to corrode in unsuitable vehicles. So although one side is that it 'cleans' the fuel systems to a degree, there are implications to consider. 

Similar to how you cannot use 'race fuel' E85+ in most cars, improper fueling has consequences. 

If we look at current brands today that offer premium fuels of varying degrees, there is still debate over whether it is worth it for your car, considering the higher costs of 'better quality' fuel and the expected fuel consumption returns and increase in power.

e10 fuel ratings

Which Fuel is Right for you?

Generally speaking, most cars should list the fuel they require or recommend on the inside of the fuel cap.

Your Hyundai i10, for example, will tell you to use unleaded fuel but may not specify to opt for any higher octane fuels. This would translate to standard 87 octane (95RON) and anything higher than this would be a waste.

On a case by case basis, some may see better performance if the engine is able to use the better fuel, but as a general rule, the manufacturer does not recommend it.

Take a Focus RS for example and the handbook will tell you:
  • Petrol of 95 RON is recommended
  • Use premium petrol with an octane rating of 98 RON or higher for optimal performance of your vehicle.
  • Fuels with octane ratings below 95 RON are not recommended and can lead to severe mechanical damage.
  • Your vehicle is suitable for use with ethanol blends up to 10% (E5 and E10).

The EcoBoost Ford Fiesta/Focus will also recommend premium fuel for optimum performance but not to the same standards as the RS model.

Will E10 damage my car?

Well, that's the £1000 question or more depending on your car. For most drivers no, always check your manual but all cars since 2011 should be cleared for E10 use. However, prior to 2002 drivers were warned not to use E10 in these cars due to the possible mechanical damage it can cause to components, seals and pipes from its corrosive properties. If your car falls between 2002 and 2011, it would be worth checking to make sure there won't be any issues, there have been reports of specific types of engines unable to run E10. 

What are the Benefits of 10% Ethanol?

“Displacing 10% of Europe’s petrol with ethanol, a fuel widely available in France, Finland and Germany, would reduce greenhouse gas emissions from petrol vehicles by over 6%.

- Robin Wright, secretary general of ePURE.

He goes on to state, "Brazil currently mixes its petrol with up to 28% ethanol, so why not Europe?”. So from an environmental perspective, yes it seems there is no losing here, of course depending on the entry price of E10, affects the efficiency for the driver and similar to premium fuels, how much does the extra investment return, either for MPG or reduced CO2?

Is E10 fuel worth it?

With all things considered, is E10 worth it to you? 

“The energy content of ethanol is about 33% less than pure unleaded... economy varies depending on the amount of denaturant that is added to the ethanol. In general, vehicle fuel economy may decrease by about 3% when using E10”.

- The Energy Information Administration

So you reduce your CO2 emissions by a few percent, but also decrease MPG by a few percent. Depending on whether you can get a Tax rebate on your new CO2 figures and the cost of E10 is cheaper, ultimately determines the value of E10 to you...