Unleaded Gasoline vs E10 Comparison Test

Without gas, most of our cars are useless, but few realize just how much this fluid, made from dead dinosaurs, has changed in the last few years and what effect it will have on their back pocket.

Apart from diesel and LPG, there are four main types of gasoline sold in Australia, including E10, Premium 95, Premium 98 and E85, and below we will tell you not only how they differ, but also which one you should use.

Fuel comparison in numbers

You will see references to 91RON, 95RON, 98RON, even 107RON, and these numbers refer to the measured amount of octane in the fuel as research octane number (RON).

These RON numbers differ from the US scale, which uses MON (engine octane) numbers, in much the same way that we use metric measurements and the US relies on imperial numbers.

In its simplest and most simplified form, the higher the number, the better the quality of the fuel. A few years ago, you had a choice of three types of gasoline; 91RON (unleaded gasoline), 95RON (premium unleaded gasoline) and 98RON (UPULP - ultra premium unleaded gasoline).

Many base vehicles will run on cheaper 91 octane unleaded gasoline, although many European import vehicles require 95 octane PULP as a minimum quality fuel.

High performance and modified cars typically used 98RON with a higher octane rating and better cleaning properties. However, these fuel comparisons have changed with new ethanol-based fuels such as E10 and E85.

E10 vs unleaded

What is E10? The E in E10 stands for ethanol, a form of alcohol added to fuel to make it more environmentally friendly to manufacture and use. E10 fuel has pretty much replaced the old base fuel we knew as "unleaded petrol" which had an octane rating of 91RON.

The main difference between E10 and unleaded gasoline is that E10 is 90% unleaded gasoline with 10% ethanol added.

Ethanol does help raise its octane to 94RON, but it doesn't result in better performance or better mileage, since the alcohol content actually increases fuel consumption due to the fuel's energy density (or how much energy you get from each liter of fuel burned). ).

The battle between E10 and 91 fuels has largely ended as E10 has largely replaced the more expensive unleaded 91.

When it comes to choosing between ethanol and gasoline, it's important to read your vehicle's owner's manual or the sticker behind your fuel door to see what the minimum fuel grade the manufacturer recommends is the minimum safe fuel for your vehicle.

If you are not sure if your car can run on ethanol, check the website of the Federal Chamber of the Automotive Industry.

Alcohol warnings

If your vehicle was built before 1986, during the leaded fuel era, you cannot use ethanol based fuel and must only use 98RON UPULP. This is because ethanol can cause failure of rubber hoses and seals, as well as gum formation in the engine, which will stop it from working.

While older cars also needed a leaded fuel additive at one time, modern 98RON UPULP can work on its own and won't harm older engines like the 91 or 95 unleaded fuel used 20 years ago when they were introduced. .

E10 vs 98 Ultra-Premium

There is a popular myth that higher octane fuels like 98 UPULP will give regular cars more performance and better economy. Unless your vehicle has been specifically tuned to run exclusively on 98RON UPULP, this is simply not true, and any efficiency improvement will come at the expense of 98's improved cleaning ability, removing built-up grime inside your engine that has already been hurting your fuel economy.

98RON UPULP usually costs 50 cents per liter more than E10 so it can be an expensive way to fill up your car with very little performance boost, although there are ethanol free benefits which means it's safe to use in all petrol cars and can help protect the engine on very hot days when there is a risk of reduced performance when using lower quality fuel.

One of the benefits of ultra-premium grade 98 fuel over cheaper gasoline options is its cleansing power. It's worth filling up your car with 98 UPULP if you're going on a long trip of several hundred miles or more, as the cleansing properties should help remove any accumulated debris inside your engine.

Tuk-tuk?

One thing that can kill an engine very quickly is detonation, also known as knocking or ringing. Knocking occurs when the air-fuel mixture in engines ignites at the wrong time due to a too hot combustion chamber or low-quality fuel.

Manufacturers recommend minimum quality fuel for their vehicles as a way to protect against knocking, as engine specifications can vary internally, and some require higher octane (RON) fuel to operate safely.

Engines in high-performance vehicles such as those offered by Porsche, Ferrari, HSV, Audi, Mercedes-AMG and BMW rely on the higher octane found in Ultra Premium Unleaded Petrol (UPULP) because these engines have a higher level of tuning and performance, which makes hotter cylinders more prone to detonation than conventional engines.

The danger of knocking is that it is extremely difficult to feel or hear, so the safest way to avoid knocking is to use at least the minimum grade of gasoline recommended for your car, or even a higher grade in exceptionally hot weather (which is why engines are more likely to to detonation).

E85 - boost juice

The sweet-smelling, high-performance E85 was touted by some manufacturers as a sustainable fossil fuel solution five years ago, but its terrible burn rate and scarcity mean it hasn't caught on, except in heavy-duty modified cars.

E85 is 85% ethanol with 15% unleaded gasoline added, and if your car is tuned to run on it, your engine can run at cooler temperatures and also produce much more power for turbocharged and supercharged vehicles. .

Although often cheaper than 98 UPULP, it also reduces fuel economy by 30 percent and, if used in vehicles not specifically designed for it, can destroy fuel system components, leading to engine failure.

Conclusion

In the end, how you drive and fill up at the low point of the weekly gas price cycle will have a bigger impact on your fuel economy than changing what fuel you use.

As long as you check the minimum type of fuel your car needs (and service it in a timely manner), the difference between 91 ULP, E10, 95 PULP and 98 UPULP will be negligible.

How do you feel about the debate about unleaded gasoline and E10? Tell us what you think in the comments below.