Learn About Different Types Of Gasoline - Subaru Service Questions in Olympia, WA

Getting overwhelmed with your options at the pump? Let the team at Hanson Subaru help! With more and more alternative fuels available for gas-powered cars, you might wonder what's safe to use and what's not; what's really better for your car and what's snake oil. We shed some light on this important issue below. After all, the gas that you put in your car matters. To keep your ride running its best, make sure to use exactly the fuel recommended by your owner's manual.

A hand operates the fuel nozzle as a man refuels his car.

5. What Is Top Tier Gasoline?

When you add fuel to your tank at the pump, you're adding a lot more than just raw gasoline. To help keep your engine running clean, gasoline sold in the United States must also include various detergents. These detergents prevent carbon build-up which would cause your engine to run poorly and develop problems over time.

Top Tier gasoline goes a step further. When you see the Top Tier logo at the pump, you know you're getting additional additives that work even harder against carbon build-up in your engine. In fact, a study from AAA says that Top Tier gas keeps your engine cleaner and can even help improve fuel economy.

This pump offers three grades of gasoline: regular, plus and premium.

4. What Is Premium Gasoline?

In addition to having different qualities of gasoline to choose from, each pump will also usually have two or three different grades of gas on offer. They might be labeled Regular, Mid-grade and Premium or something similar. You'll notice the octane rating goes up as you go up in price. The higher the octane rating, the more compression the gas can withstand before it ignites.

In ordinary passenger cars, this doesn't have much benefit, and you'll be fine using Regular gasoline. Adding Premium fuel to a car that doesn't require it doesn't really "clean the engine." While some people like to "treat" their vehicle to a tank of Premium gas from time to time, it's a car, not a golden retriever. It'll be just fine using regular fuel every time.

However, in some high-performance cars, premium fuel is required. That's because high horsepower engines often have higher compression ratios that demand a higher octane rating. Consult your vehicle's owner's manual to find the octane rating required for your engine.

(And don't worry -- when you visit a Top Tier filling station, you're getting all the extra detergents whether you choose Regular or Premium).

An array of fuel nozzles are color coded, letting you know which fuel each one offers.

3. What Is E85/FlexFuel?

Did you know most gasoline sold in the United States is at least 10% Ethanol? Ethanol fuel is derived from plants like corn and sugarcane, and the United States makes more of it than anywhere else in the world. There's hope that using Ethanol can help reduce the environmental impact of gasoline.

Some vehicles are available with FlexFuel engines that can run on E85 fuel. E85 is a blend of 85% ethanol and just 15% gasoline. Accidently putting this fuel in a regular car will cause the engine to run poorly and very inefficiently, but it shouldn't cause any lasting damage.

2. What Is E15 Gasoline?

Like we mentioned above, most gasoline sold in the United States already contains 10% Ethanol. At the latest gas stations, you may now see a new option: E15 gasoline. E15 gas is 15% Ethanol, which isn't as much as E85, but it can be safely used in just about any modern car that runs on gas! You may even find ethanol blends like E20 and E30 that are growing in popularity. Check the label on the pump: It'll often say that the fuel is safe to use in any car built after 2002.

1. What Is Diesel?

All of the options we've discussed above are different types of gasoline -- diesel fuel isn't gasoline at all! It has a much lower octane rating since diesel engines don't use a spark to ignite the fuel. Instead, the fuel is simply compressed. Diesel fuel is so volatile that it combusts under enough compression. Diesel engines are impressively efficient, but you don't find many of them in ordinary passenger cars because they don't tend to generate much horsepower. They're better suited for heavy-duty pickup trucks, semi-trucks and other high torque applications.

Remember: while it's not ideal to put a different kind of gasoline in your car's engine, putting diesel in a gas-burning car will cause the engine to completely shut down. You'll most likely need to get some expert help from expert service technicians to remove any traces of diesel from the fuel system.

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Hanson Subaru

2300 Carriage Loop SW
Directions Olympia, WA 98502

  • Call or Text Sales: 360 943 2120
  • Service: (360)943-8531
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  1. Hanson Subaru

    2300 Carriage Loop SW
    Olympia, WA 98502

    • Sales : (888) 490-9863