But using E10 petrol in an incompatible vehicle will, over time, cause problems in the fuel system. Carburettor corrosion, fuel hose degradation, fuel filter blockage and damaged fuel pumps are all likely if you use E10 regularly in vehicles that shouldn't take it.
Premium, 98 Unleaded Petrol
Otherwise known as Ultra-Premium by some brands, 98 is the highest-octane fuel currently available in Australia. Unleaded 98 provides higher engine power and overall performance in comparison to 91 and 95. It is also responsible for less pollution, according to providers.
Most petrol vehicles built after 2000 are compatible with E10. If your car is E10 compatible you can replace your unleaded petrol with E10 when you fill up. It's ok to switch back and forth between E10 and other unleaded fuel types, where your manufacturer has advised these fuels are suitable for your vehicle.
Your drivers who fill up with E10 will get fewer miles per gallon due to it containing 5% more ethanol. This reduction is said to be very small in comparison to the reduction in CO2 released in the atmosphere, but it is something to consider when planning your fuel costs.
Although E10 is cheaper at the pump, it will burn quicker than your premium fuels. This is due to the higher octane rating of premium fuel (Unleaded 98) compared to E10 (Unleaded 91/94).
For these older cars, experts have warned that the increased ethanol content is likely to lead to issues in the long term, the most common being blocked fuel filters, damaged fuel pumps, the rapid degradation of fuel lines and corroded carburettors.
CAN I MIX E10 AND REGULAR UNLEADED? Not like diesel and petrol, you can refuel with E10, regular or premium unleaded without any damage to the fuel system or engine.
If your car was built after 2010, it will be compatible with E10 fuel. If it was built between 2000 and 2010, it will likely run on E10 fuel. However, there are some exceptions, including models from major brands like Ford, Toyota, Volkswagen, Audi and Mercedes.
While E10 is a cheaper option than 91 Octane (91 RON) fuel, it typically has an octane rating of 94.5, putting it in line with the middle of the range 95 RON option. Ethanol is a cleaner-burning fuel than 91 RON too, resulting in less pollution of the atmosphere.
If 91 is used in cars requiring higher octane fuel, you run the risk of pre-igniting or "knocking". This occurs when the petrol combusts early and pushes down against a piston while it is still moving upwards during the compression stroke.
While high-octane fuel is preferred for classics, they can run perfectly well on lower octane petrol, especially if the ignition is adjusted to counteract the change in combustion rate.
Therefore, if your classic is not used for a while, it is advisable to refuel a premium gasoline with the lowest possible alcohol content (Super 98, V-Power, Excellium, etc.). Some suppliers are offering additives for E10, specially designed to counteract the harmful effects on our classics.
Most, but not all, modern cars can use E10, so it's important you check first before filling up with E10 fuel. The Federal Chamber of Automotive Industries says some E10 unleaded petrol blends are marketed as 94 RON. That means they do not meet the fuel standards for cars recommended to use 95 or 98 premium fuels.
Mixing the grades to get 91 or so shouldn't hurt, but it probably isn't saving you much money. Using anything higher than your manual recommends probably won't help your car's performance – but using lower might save you a few bucks, Leroux says. If you notice knocking, you should switch back.
Super-unleaded fuel is mostly used by performance cars but is fine for any petrol car, unlike the new E10 fuel. When you pull up at the petrol station you're often faced with two types of petrol: unleaded and super-unleaded.
For modern classics there are catalyst-friendly additives available such as Millers Ethanol Protection Additive or Lucas Oil Ethanol Fuel Conditioner, but your best advice is to check with the vehicle manufacturer or an owners club.
Ethanol is corrosive so with a higher percentage of ethanol in E10, there's more risk of corrosion on metal, plastic and rubber in your classic car's fuel system. This can cause many problems, from broken fuel lines to carburettor issues.
“But E10 burns slightly less efficiently than premium unleaded meaning that drivers who opt for premium unleaded petrol will get a few more miles to the gallon.” The fresh warning comes just after some experts warned that E10 fuel was having a massive effect on efficiency.
Shell Unleaded E10, which contains up to 10% ethanol, has a minimum 94 octane rating.
Using 98 might give 3 per cent reduction over 95, again assuming the computer adjusts the engine parameters. But fueling an engine with 95 or 98 won't necessarily open the door to earth shattering performance or extreme levels of fuel economy if the engine is not specifically designed to run on it.
95 petrol works as well, but if your engine is powerful, it will use higher pressures that 95 petrol may not be able to withstand. If you want to be on the safe side, 98 petrol will offer your engine better protection.
Ethanol has lower energy content than petrol, so generally speaking it provides less 'bang for your buck'. ABMARC says this means that you probably won't drive quite as far on a tank of E10 as you would on a tank of unleaded (91 RON) or 95 RON.
The problem with Ethanol Blends E5 and E10
Fresh petrol in a full sealed container stored in a cool place can stay usable for up to 12 months. In a container that is not full or sealed it can become unusable in less than 6 months and in a warm environment less than 3 months.
While a car not designed to run on E10 will likely not suffer engine damage, the ethanol can damage fuel lines and other parts of the fuel system, leading to longer term problems. E10 emissions can also damage the core of catalytic converters.