Have you ever showed up to the gas station and seen all of the different options and thought, "Man, which one am I supposed to use?"
If you have, don't worry its happens to all of us. The answer to this really depends on what vehicle that you are driving and what kind of fuel it requires. First things first, we need to realize that all fuel pumps are different but there is one part that is really similar and that is the octane ratings.
What is octane? Octane is a measurement of a fuels ability to resist detonation due to compression or heat. Simply put, the higher the octane rating the higher the temperature before the fuel will spontaneously combust. This means that certain engines need a higher octane fuel to resist pre-detonation. Pre-detonation is very serious condition where the fuel mixture explodes before the piston reaches the top of its stroke. When this happens it attempts to force the engine to spin backwards. This causes very rapid wear to your engine and can cause catastrophic failures such as a broken piston or connecting rod. At the very least it will cause reduced performance and driveability issues.
Now contrary to popular belief you should only use the lowest octane rating of gasoline that your vehicle requires. While using a higher grade will not hurt your engine, you will not see a benefit from using it, and it will also cost you more money. If you want to read more about octane ratings and how they effect engine performance you can read about it here.
"How do you know what fuel grade your vehicle needs?"
How do you know what fuel grade your vehicle needs? The majority of vehicles on the road today only require 87 octane, if you see nothing stating otherwise, this is what you should use. Now, on the other hand, if your vehicle does require a higher grade it will usually be shown in a pretty visible location such as on the fuel cap, fuel door, or on your fuel gauge. If you are unsure and want to verify 100 percent you should look at your owners manual,it will tell you exactly what you should use.
We know now that we should use the lowest octane rating of fuel that our vehicle requires and that doing anything more will cost you more money, but what about the other options? Now we really need to talk about the ethanol and which one is right for you When you are at the pump there are usually a couple of different options such as E0, E10, E15, E30, and E85 these fuels each have their uses but you need to be informed what those benefits are before you make a choice.
E0-This option is whats known as "ethanol free" gas it is not available at every store and it is usually only available as a premium fuel. What this means to you is that it will probably be your most expensive option. we would recommend you use it in your small engines like those found in a weed-eater, dirtbike, chainsaw, or lawnmower. If you want to read more about why visit our FAQ page.
Why we like it: It is a great option for small engines.
Why we don't: It is the most expensive option and you will have to search for a gas station that carries it.
E10- This option is the standard choice that almost everyone will use, most people don't realize it, but the majority of gas sold today will include 10% ethanol. What this means to you is that unless it is specified otherwise all options such as 87, 89, and 93 will include at least 10% ethanol. This has been true since 2005 with the adoption of the renewable fuel standard. You can read more about why we include ethanol in our gas here.
Why we like it: It is the cheapest option for fuel and it is widely available.
Why we don't: We really don't have an answer for this one...
E15- This option is only available at select locations and it really isn't much different than E10. This is an option for people who would like to use more renewable fuels but it is only certified for use in vehicles produced after 2001. That doesn't mean it wont work in older vehicles it just means that the manufacturer hasn't fully tested it. Heads up though Things are changing. The EPA is debating making E15 a replacement for the E10 fuel standard.
Why we like it: it more of our locally grown renewable resources and reduces emissions.
Why we don't: Lower fuel economy compared to E10, only certified for use in vehicles 2001 and newer.
E30- This one kind of falls through the cracks. It can be used in flex fuel vehicles but it's not found at very many stations. just as with the E15, this doesn't mean that you cant use E30 in your in vehicle, but it does mean that the manufacturers haven't tested it. Check out the E30 challenge to learn more.
Why we like it: It can be used in a non flex fuel vehicle although it has not been tested on all vehicles.
Why we don't: It is not available at most fuel stations and there is a noticeable drop in fuel economy.
E85- This is the highest percentage of ethanol that you can get in a gallon of gas. This should only be used in a flex fuel vehicle. Flex fuel vehicles have special components to measure the amount of ethanol in your fuel and larger injectors to compensate for the lower fuel density(this is very basic, there are a lot of other changes too). You definitely should NOT use this in a non flex fuel vehicle. It will not cause any catastrophic engine damage but you will probably see a check engine light come on along with reduced power from your engine. If you do put some in your tank on accident the best solution is to fill your tank up the rest of the way with a regular unleaded fuel(87 octane). this will dilute the ethanol that is already in your tank.
Why we like it: It has the lowest emissions of any of the fuels listed, 85% of the fuel is renewable.
Why we don't: There is a drastic drop in fuel economy (19% compared to E10), currently this option costs more per mile than all other options except for E0.