Regular Unleaded Gas? What Different Gasoline Types Mean

March 23, 2017

Image Courtesy of Pixabay

Buying gasoline is something we all do every week or so. It's not something many people put a lot of thought into. There are three basic types: regular, mid-grade, and premium. Once you have found out which type is best for your car (and you can afford) you stick to it. Here is some information to consider about gasoline. Your car will appreciate the effort here.

The Quick History of Unleaded Fuel

In the early 1900s, all gasoline had lead (and burned lead) for the daily driver. As we know now, lead is extremely toxic! In the 1970s, efforts were being made to phase-out leaded fuel, but people were still more concerned with the higher costs of unleaded fuel versus its counterpart. In the mid-90s, leaded gasoline had been almost fully phased out, but the term "unleaded" has continued to be used when you visit the pump.

Is There A Way To Find The Best Gas Stations?

Gas stations universally sell the same gas, so none are technically "better" compared to the other. Some gas stations, such as Chevron, will boast special additives, like Techron, which is an additive actually developed by Chevron, but other than that, you're getting the same thing no matter where you end up.

So, How Do I Know Which Gasoline To Use – 87, 89, or 91?

Look in your user manual or on the inside of your fuel door. If you still aren't sure, call a dealer and they can assist you.

Great, now I'm at the pump and there are multiple options – what should I do? There are three options at the pump typically. These are regular, mid-grade and premium gasoline. To the consumer, the only difference may look like the price. In our article, "Can I Use Regular Gas When The Owner's Manual Says Premium?" we mention that high-octane gasoline isn't necessarily a "Good, Better, Best" situation. 

That premium gasoline with higher octane content may resist knocking better than its lower-octane counterpart, but most engines are designed to take regular gasoline just fine. If you don't mind giving up on performance, your car should run fine on regular gasoline when the manual says premium. The same also applies vice-versa: using premium in your gas tank when your car normally demands regular won't improve your vehicle's performance around town and might just end up costing you more.

Another way that many people try to improve the efficiency of their car is by adding additives to their gas tank. The idea here is that the additive will make help the car get more power from the gas or make the gas last longer than typically expected. 

While there are many types of additives, here is a run-down of some of the more popular:

Oxygenators increase the oxygen in the engine and reduce carbon monoxide emissions.

Metal deactivators inhibit sticky residue from forming on engine parts.

Corrosion inhibitors slow down metal corrosion.

Dry gas reduces the amount of water in the tank and stops water contaminated gasoline from freezing.*

*According to, this is not usually a part of car maintenance but if you think that your car may have some water in the tank, it's best to utilize it. If water is inside the engine you will notice hesitation and have trouble accelerating.

Water can cause corrosion throughout the engine and can freeze in cold temperatures. This could cause serious problems for your engine. If you know that there is water in your tank, you have two options. Adding dry gas to your tank to reduce the water or to siphon all the old gas out of your tank and replace it. If you do not know how to siphon get to a mechanic. Engine problems are big problems.

So now you know and you can decide what's best for your car and your pocketbook.

RepairPal is working to mend the lack of trust consumers have in the car repair industry by providing them with in-depth knowledge and resources that connect them with dependable and reliable car repair shops near them.

Our goal is to establish an auto repair process that is less stressful and much more trustworthy for everyone involved. Our website hosts a car repair Estimator that gets rid of that "ripped-off" feeling. We also provide matches to local Certified shops that are guaranteed to do repairs with quality parts, a fair price, and a trained, awesome staff.

Have a question about RepairPal? Send us an email at

About the Author

RepairPal is the leading online source of auto repair resources and estimates. With many ASE Master certified mechanics on staff who have decades of experience, RepairPal knows all the fine points of car repair.

1 User Comment

Sign in to comment
By , July 12, 2017
Love this article, had tons of questions about this, this article answered all of them. thanks!