Can I Use E85 In My Subaru Outback? Quick Answer

This article is about Can I Use E85 In My Subaru Outback? Prior to 2009, ordinary unleaded gasoline with an octane rating of 87 (2.5L non-turbo) or 91 (3.0L and 2.5L turbocharged) was used in Subaru Outbacks. All Outbacks began utilizing 87-octane regular unleaded gasoline after 2009.

That, however, only partially conveys the situation. We’ve provided suggestions and specifications below: Can I Use E85 In My Subaru Outback? We’ll also greatly discuss the Outback’s compatibility with oxygenated mixes. We also talk about the size of these generations’ tanks. Continue reading!

Can I Use E85 In My Subaru Outback?

MMT additives are incompatible with a Subaru Outback, but reformulated fuels are compatible. These fuels are made to burn more cleanly. Additionally, it would help if you avoided gasoline with more than 15% ethanol, so don’t buy E30 or E85 at the pump.

When Does It Make Sense To Switch To E85?

Running E85 can provide a turbocharged Subaru with some noticeable advantages.  It has a very high effective octane rating, which makes it particularly resistant to detonation and pre-ignition. Additionally, because it is an alcohol-based fuel, it has many cooling advantages. 

In a stock WRX or STI, you will probably notice the difference if you switch to E85, but there may be even more advantages for high-power builds, race cars, and vehicles like the FA20DIT WRX, which has much higher compression than the WRX and STI that were built with the EJ series engines.

The decrease in fuel efficiency is one of the greatest negatives, but there are other negative effects. On newer automobiles, there may even be warranty problems. We examine the advantages of E85 and when and when it makes sense to consider converting to this fuel for this week’s question of the week.

There is also the issue of Flex-Fuel, which was one of your greatest options for performing this conversion in a street car up until the past week or two.  However, Cobb withdrew their Flex-Fuel kits just before we began production on this video, so that adds another layer to this choice, which we also talk about.

Fuel Requirements per Generation

• Regular gasoline with an octane rating of Eighty-seven is used in 2.5L non-turbo Subaru Outbacks built between 1998 and 2009. 91 octane is advised for usage in the 3.0L non-turbo engine, while 87 octane can be temporarily substituted. 91 gasoline is required for the 2.5L turbocharged engine, and 87 octane should not be utilized.
• All engine types in Subaru Outbacks built between 2009 and today use standard unleaded fuel with an octane of 87.

Premium Gasoline

It’s crucial to discuss premium gasoline now that you are clear on which fuel to use with which model year and engine type. This is due to the fact that many people question whether premium gasoline isn’t generally a superior option, especially for the engines for which regular fuel is advised.

It is crucial to understand that only engines that run on premium gasoline (91 octane or higher) would benefit from it. If the engine is not built for premium gasoline, higher octane fuel has no performance or durability benefits for the Outback.

Instead, you’ll be forced to pay more for less-effective gasoline for your vehicle. As a result, it is advised that you follow the recommendations above. Additionally, using standard gas when premium gas is advised will harm the engine and fuel system.

Reformulated Gasoline

The usage of reformulated gasoline is another issue we must discuss. The reformed gasoline is intended to burn cleaner than conventional, unreformulated gasoline. Initially made required in California, this type of fuel is now required in more than 19 states and areas around the US.

There are regulations governing the use of reformulated gasoline, particularly in locations where the air quality is poor. It’s comforting to know that all Subaru Outback generations are completely compatible with reformulated gasoline.

The usage of this fuel is advised by Subaru wherever it is accessible. Additionally, you won’t need to perform any additional maintenance and get the same fuel efficiency as you would with conventional, non-reformulated gasoline.

Oxygenated Blends Such As E-85

Other than reformulated gasoline, several varieties of gasoline also contain ethanol, methanol, or MTBE. It’s crucial to be aware that these fuels work with the Outback, albeit you’ll need to pay great attention to the ratios utilized in your fuel. These are the regulations:

Methanol-containing fuel is compatible with all Subaru Outback versions. However, it should contain no more than 5% methanol at most. To prevent damage to the fuel system, the fuel should also be accompanied by adequate amounts of the right cosolvents and corrosion inhibitors.

Subaru Outbacks produced before 2019 are only permitted to utilize fuel containing a maximum of 10% ethanol (E-10); E-15 and E-85 are prohibited. The maximum ethanol content of fuel for Outbacks manufactured after 2019 is 15% (E-10 and E-15), while E-85 is not permitted.

All Subaru Outbacks can use MTBE-containing fuel, although only up to 15% MTBE should be included. When these rules are broken, the engine will knock (more on that in the subsection below), the check engine light will brighten, and the car will slow down to prevent severe damage.

Online, you may find a variety of gasoline additives that, according to their advertising, will either help your Outback’s fuel work at its best or make the fuel system and engine last longer. For the Outback, Subaru strongly warns against using these fuels.

This is due to the fact that some additives contain silicon or metallics that, when employed, might harm the fuel system and engine. The vehicle’s warranty does not cover damage brought on in this manner.

Subaru urges you to follow the recommendations we’ve made so far in this post regarding fuel quality rather than utilizing additives. Additionally, it is advised that you only purchase fuel from licensed TOP TIER gas shops.

ToptierGas.com can be used to locate these retailers. All the additives your Outback needs are in TOP TIER gas. This will boost the car’s performance and simultaneously clean the engine of any potential deposits.

After Refueling, The Engine Starts To Rattle

In some instances, the engine will make a knocking noise. Please be assured that any knocking noise is completely natural. It’s possible to hear a very tiny engine knock, especially when the engine is operating at or close to maximum capacity.

However, there is a concern when this knocking sound gets louder and louder. You could have a serious issue, especially if you recently filled up your car. In this instance, you most likely utilized fuel with a lower octane level than is advised.

It would help if you stopped the automobile when you heard a loud knocking and called your dealer. The fuel you are presently using needs to be removed from your car. The fuel filter must also be changed, and the vehicle’s memory must be reset by unplugging and replugging the battery.

What Is Top Tier Gasoline?

The gist of it is that Top Tier gas has the best blend of additives and cleaners above and above what is legally needed.

The lengthy response is that there is little distinction between pure gasoline. However, once gasoline is in the hands of various businesses, they add various detergent chemicals.

Some of these additions, which aid in preventing carbon buildup and other problems, are mandated by law. Best-in-class gas companies go above and above by including more detergent ingredients than are necessary. In addition to further lowering exhaust emissions, your engine remains clean.

Do I Need Premium Gas For My Car?

Regular unleaded, mid-grade, and premium petrol can be found at most gas stations. Typically, these will also have 87, 89, and anywhere between 91 and 93 designations. The octane rating appears as numbers.

There will be a minimum octane rating for your Subaru, and you shouldn’t go below it. This varies depending on the model: while most Subaru vehicles only need 87 octane fuel, the most recent Subaru WRX demands at least 91, while the Subaru WRX STI and Subaru BRZ demand at least 93.

What about filling your car with higher-octane fuel? You shouldn’t put fuel in your tank that is less octane-intense than is advised. You can, but there isn’t really a good reason to. You won’t gain any more advantages by doing this. Rather, adhere to the suggested octane rating.

What Is Flex Fuel/E85?

Most of the time, gasoline contains up to 10% ethanol and other necessary additives and is not pure gas. This biofuel, made from corn or sugarcane, could make your Subaru more environmentally friendly. E85, or Flex Fuel, is a mixture of 85% ethanol and 15% gasoline. However, there are other ethanol mixtures as well.

However, only Flex Fuel Vehicles should utilize this gas. It might interfere with the car’s fuel system if added to an engine that isn’t equipped with it. Check your owner’s manual or contact our dealership service department at Shingle Springs Subaru to determine if your specific Subaru model can utilize E85.

Which Gas Is E15?

Some gas stations also sell E15 fuel. This composition is the opposite of E85: it contains 15% ethanol and 85% gasoline. E15 is typically manageable in newer vehicles, but you can always read your handbook to ensure.

How Does Diesel Fuel Work?

Diesel fuel is a byproduct of the production of gasoline and is an oil. Did you realize that spark plugs are completely absent from diesel engines? This is because diesel fuel will not function in a gas engine since it spontaneously ignites under pressure without a spark.

Since Subaru doesn’t currently provide a diesel engine, you won’t have to worry about finding a diesel fuel pump if you drive a new Subaru vehicle. Since the nozzle is too huge to fit contemporary gas-powered cars, you’ll likely need more time to unintentionally fill your modern Subaru with diesel fuel.

Conclusion

I have covered the answer to Can I Use E85 In My Subaru Outback? These are the main fuel types that are available. They are not the only things that can propel automobiles, though.

More electric quick-charge choices will be available at petrol stations as hybrid, and electric vehicles become more common. Expect more hydrogen refueling stations if automobiles fueled by hydrogen gain traction on the market.

Frequently Asked Questions