If you’re like many drivers, you buy the regular unleaded gasoline and don’t think much about the different types of gas.
For those who are curious about whether to buy premium or regular gas, this short guide will explain the different types of gas for cars and what you should know.
What makes up gasoline?
According to the Energy Information Administration, “gasoline is a fuel made from crude oil and other petroleum liquids. Gasoline is mainly used as an engine fuel in vehicles. Petroleum refineries and blending facilities produce motor gasoline for sale at retail gasoline fueling stations.”
The gasoline you’re used to is actually unfinished gasoline combined with additional liquids such as ethanol. It’s these different blends that determine the different types of gas that are typically listed by grade at the gas pump.
Different types of gas by grade, explained
There are three different types of gas at most U.S. gas stations, typically differentiated by their octane ratings:
- Regular gas (typically 87 octane) is one of the most common fuel types. Many car manufacturers recommend regular gas, and it’s many drivers’ go-to option. Regular gas is a budget-friendly gas option and is standard for many vehicles.
- Mid-grade gas (usually 88 to 90) is a specialty gas. Some vehicles are made to run on gasoline with a higher octane level. For example, some sport-utility vehicles (SUVs) require mid-grade gasoline. The higher octane level can be good for performance.
- Premium gas (often 91 to 94) is often the highest octane gas sold. A car rarely needs premium gasoline, but some vehicles designed for high performance may require a higher octane level.
You might also see the different gas grades referred to as unleaded, super, or super-premium.
Using the right fuel for your vehicle can boost its performance and efficiency. If your car doesn’t require a higher octane level, there’s no need to use a more expensive type of gas. It could even potentially damage your vehicle if you fill up with the wrong type of gas.
Understanding premium gas vs. regular gas
When you’re reviewing different types of gas, it’s important to note that the octane level measures the gasoline’s compression.
The main difference between premium gas and regular gas is the octane rating. This affects the engine’s performance and compression.
Aside from that major difference, of course, there’s the difference in price points as well.
Regular unleaded gas is typically the cheapest gas to purchase, as it is the most common.
Premium gas is typically the most expensive gas to buy. Some luxury car manufacturers and manufacturers of sports cars or foreign cars recommend higher-octane, premium gas to achieve the best engine efficiency.
Double-check whether your car manufacturer requires premium or recommends premium gas. Your vehicle owner’s manual will tell you which gas you should use to get the expected vehicle performance.
Should I buy mid-grade gas?
Few car manufacturers suggest mid-grade gas. It has slightly more additives than regular gas, but generally, the results won’t be noticeably better.
If your vehicle doesn’t require mid-grade gas, you’ll be spending extra money without getting a meaningful improvement.
What kind of gas should I get for my vehicle?
When it comes to types of gas for cars, your car owner’s manual will list the recommended gas for your exact vehicle.
Don’t splurge or use more premium gas because it won’t necessarily allow your vehicle to run faster or get better gas mileage if it only needs regular gas.
Can I use diesel for my car?
Diesel fuel has a much lower octane rating of 25 to 30. If your car manufacturer doesn’t recommend diesel, you shouldn’t fill up your car with it, even if it costs less than regular gas.
Diesel can cause damage to your vehicle’s engine because of the lower compression and octane level. You don’t want to get stuck with costly and unneeded car repairs.
Is the type of gas you use important to your car’s health?
You want to keep your car in good shape, so you may think splurging on a higher octane rating is better. Not exactly.
If your car manual calls for a premium or mid-grade gas, but you pump regular gas instead, the lower octane level could reduce engine power, damage your car health, and lower fuel economy.
In contrast, filling your car up with premium gas when your car owner’s manual calls for regular gas may not damage your engine, but it probably won’t do much besides costing more money.
How does regular car maintenance keep your vehicle in good health?
Keeping up with regular maintenance like oil changes, having the proper tires, and being aware of any issues can help keep your car in good health. An easy way to keep your car running in tip-top shape for longer is to drive less.
Low-mileage drivers put less wear and tear on their cars. Driving less frequently generally means you’ll need to maintain your car less frequently, too.
Switching to pay-how-you-drive auto insurance could be a good idea if you don’t drive much. Metromile’s pay-per-mile insurance policies focus on the miles you drive, so people who don’t fill up often could also pay less for car insurance.
The table below shows the average annual car insurance savings enjoyed by new Metromile customers:
If it’s an option, taking public transportation could also help you save money at the gas station.
The bottom line
There are many types of gas out there. If you want to save money on gas and keep your car healthy, stick to what your car manufacturer suggests. It’ll save you money and hassle.
If you don’t drive much and are rarely at the gas station, you can get a free quote from Metromile and try pay-per-mile auto insurance (you’ll need to keep your current policy to remain covered) with the free Ride Along™ trial before making the switch.
Melanie Lockert is a freelance writer, podcast host of the Mental Health and Wealth show, and author of Dear Debt. She’s a cat mom to two jazzy cats, Miles and Thelonious, an amateur boxer, music lover, and needs coffee to function.