It is believed that the higher bioethanol content in E10 petrol could dislodge deposits in older engines and fuel systems, causing blockages; it could also cause some seals, gaskets, metals and plastics to corrode.
E10 petrol's higher bioethanol content is corrosive to rubber parts, gaskets, seals, metals and plastics, which causes engine damage, so it could dislodge deposits in older engines and fuel systems, causing blockages. It should only be used with expert advice, which means pretty much never.
The consequence of putting E10 fuel in an incompatible vehicle depends on the vehicle/engine variant and how much fuel has been put in. It may cause some pre-detonation ('pinking'), and perhaps a little rough running and poor cold starting, but it shouldn't be a disaster for the driver.
The problem with E10 is it contains less energy than petrol, so E10 burns quicker than premium unleaded (95 and 98 octane).
If your car runs an Octane Rating of 91 (most petrol cars use this), then E10 fuel is interchangeable with your regular petrol. Cars that use premium fuels (with an octane rating of 95 or 98) are better off with that running through their engines, as they're tuned to require high efficiencies from the fuel system.
No, you'll end up with an octane rating somewhere between the two fuels depending on how much of each you used. E10 has an octane rating of at least 94, so the mix will be between 94 and 98.
Because the energy provided by the ethanol is less than the energy provided by pure petroleum, E10 has around 3% less energy than the equivalent amount of RON 91 petrol.
The energy content of denaturant is about equal to the energy content of pure gasoline. In general, vehicle fuel economy may decrease by about 3% when using E10 relative to gasoline that does not contain fuel ethanol.
Why could E10 damage my classic car? It's all down to that double dose of ethanol. Ethanol is hygroscopic: it attracts water and absorbs moisture from the air, causing condensation and, in the long-term, the corrosion of car parts like carburettors, fuel lines and fuel tanks.
“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”.
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.
Research by the Environmental Protection Agency (EPA) showed a 3% to 4% reduction in fuel economy using E10 compared with pure oil-based petrol – despite the U|K government saying it's only around 1-2%.
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.
What is the octane rating of Shell Unleaded E10? Shell Unleaded E10, which contains up to 10% ethanol, has a minimum 94 octane rating.
These deposits end up in your fuel injectors, which causes misfires and engine management lights (ECU, EML, or Check Engine Light) to come on. If you're worried about the long-term effects of using E10 unleaded in your vehicle, it's best to stick to the super unleaded, E5.
The good news is that all new cars manufactured since 2011 are compatible with E10 petrol. However, there are some cars that might not be compatible with E10 petrol: Classic cars. Some specific models of car, with most being manufactured from the early 2000s.
One of the areas that E10 can have a negative impact is in your fuel systems' seals and gaskets. These are often made of rubber on older vehicles, a material than Ethanol will degrade much faster than petrol.
Shelf-Stable Gas: Up to 3 Year
The type of gasoline that has the most extended shelf life is shelf-stable gas. Fuel stabilizers are available for purchase online and at local hardware stores and are petroleum-based additives that can be added to gasoline before storing it in your garage.
All cars with petrol engines are E10 (EN228) compatible since 1st January 2000. Older petrol cars should continue to use E5.
E10 - the new standard unleaded petrol (95 octane)
E10 fuel comprises around 10% bioethanol and 90% petrol, and has a 95 octane rating. It emits less carbon than the old standard unleaded petrol and has been used on mainland Europe, Australia and North America for years.
Premium unleaded 98 octane petrol: This petrol is designed specifically for high performance engines. This will definitely work if your car needs premium fuel, and may offer better mileage over 95 octane fuel. E10 fuel: This blend of ethanol and unleaded fuel is cheaper than 98 octane and has an RON of 105.
Does adding 10% alcohol to gasoline cause an engine to produce more horsepower? No. Alcohol has less energy per unit volume than gasoline. Alcohol is added to gasoline to reduce the amount of gasoline the US uses, not to “improve” anything.
What qualifies as fuel efficient, then? Anything that is listed as less than 6-litres/100km or more than 16.5km/1-litre is considered to be pretty good. The first (and most common) reference is litres per 100km (litres/100km). This is how many litres of fuel the car needs in order to travel 100km.
Mixing the 95 and 98 octane fuels will not cause any problems.
E10 vs 98 Ultra-Premium
One area 98 ultra-premium fuel excels over the cheaper petrol options is its cleaning ability. It is worth filling your car with 98 UPULP if you are going on a long trip of several hundred kilometres or more, as the cleaning properties should help remove any built-up gunk inside your engine.