Different Types of Gasoline - information from the the pros at Shingle Springs Subaru serving Sacramento, CA

Refueling your Subaru may seem as simple as rolling up to the pump and filling up. But when it comes to fuel, you may notice that there are lots of options. You may even wonder if you're using the best choice for your Subaru.

At Shingle Springs Subaru, we're here to help. We've put together important information pages like this one to help you better know your Subaru. We've already talked about the importance of choosing where to get gas. Below, we'll walk you through what you may see once you're at the station.

A person giving a thumbs-up sign as they refill the tank.

6. What Is Top Tier Gasoline?

The short answer: Top Tier gasoline has the best combination of additives and detergents beyond what is required by law.

The long answer: there's no real difference between pure gasoline. But once gasoline gets into the hands of different companies, they add different detergent additives. Some of these additives are required by law, and they help prevent carbon buildup and other issues. Top Tier gas brands go above and beyond, adding more detergent additives than are required. This makes sure to keep your engine cleaner while further reducing exhaust emissions.

Gas pump with different octane levels.

5. Does My Car Need Premium Gas?

Most gas stations have regular unleaded, mid-grade, and premium gas. Usually, these will also be labeled as 87, 89, and anywhere from 91 to 93. The numbers are the octane rating. Your Subaru will have a minimum octane rating, and you shouldn't go below that. This varies by model: while most Subaru models only require 87 octane gas, the latest Subaru WRX requires at least 91 octane, while the Subaru WRX STI and the Subaru BRZ both require at least 93.

You shouldn't fill your tank with gas that has a lower-than-recommended octane level, but what about filling your car with higher-octane gas? While you can, there's no real reason to. Doing so won't give you any extra benefits. Instead, stick to the recommended octane rating.

4. What Is E85/Flex Fuel?

The gasoline at most places isn't pure gas and required additives: it's also mixed with up to 10% ethanol. This is a corn- or sugarcane-based biofuel that may help make your Subaru more eco-friendly. However, there are other ethanol combinations, as well, including E85.

E85, also called Flex Fuel, is made with 85% ethanol and 15% gasoline. However, this gas should only be used with Flex Fuel Vehicles. Adding it to an unequipped engine may cause problems with the vehicle's fuel system. To see if your Subaru model can use E85, check your owner's manual or contact our dealership service center at Shingle Springs Subaru.

An old, worn-down diesel pump. 

3. What Is E15 Gas?

Some gas stations have E15 gas, as well. This is essentially the opposite of E85 in makeup: it's 15% ethanol and 85% gasoline. Newer cars can generally handle E15 perfectly well, but you can always check your manual to be sure.

2. What Is Diesel Fuel?

Diesel fuel is actually an oil, and it's a byproduct of the process that makes gasoline. Did you know that diesel engines don't even have spark plugs? That's because diesel fuel ignites under pressure without the need for a spark, and this fuel simply won't work in a gas engine. If you drive a modern Subaru model, you won't have to worry about finding a diesel fuel pump since Subaru doesn't currently offer a diesel engine. In fact, it's not likely that you'll even be able to accidentally fill your modern Subaru with diesel fuel since the nozzle is too large to fit modern gas-powered vehicles.

1. What Else Is There?

These are the main types of fuel you'll find. However, they're not the only things that can power vehicles. As hybrid and electric cars become more prevalent, you'll find even more electric quick-charge options at gas stations. And if hydrogen-powered cars find a foothold in the market, expect more hydrogen refueling pumps, as well.

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Shingle Springs Subaru

4045 Wild Chaparral Dr
Directions Shingle Springs, CA 95682

  • Sales: 530-677-8771
  • Service: 530-677-8771
  • Parts: 530-677-8771