What Powers Your Subaru? Four Types of Gasoline You Should Know About

September 15th, 2023

When you arrive at the gas station, choosing the cheapest available fuel might seem convenient, but is it the right one for your Subaru engine? Let's delve into the various gasoline options and their potential impact on your vehicle at Nate Wade Subaru. It's common practice for many drivers to opt for the least expensive gasoline without considering the specific needs of their cars. However, the type of gasoline you choose can significantly affect your engine's performance and longevity. For instance, in Utah, regular unleaded gasoline typically has an octane rating 85. Still, you may notice options with higher octane ratings, such as "Premium" gasoline with ratings in the 90s. Premium gasoline is crucial for specific Subaru models like the WRX and BRZ, which have higher compression ratios. Using regular unleaded fuel in these vehicles can lead to premature combustion and potential engine damage.

Moreover, there's TOP TIER^™ gasoline, which exceeds minimum legal requirements by incorporating extra additives to maintain a cleaner engine. While it may come at a slightly higher price, the long-term benefits include reduced maintenance costs, fewer fuel injector cleanings, and improved fuel economy. In conclusion, the choice of gasoline should be made considering your Subaru's specific requirements to ensure optimal engine performance and longevity, making it a wise investment in the long run.

Understanding Gasoline Types

In Utah, regular unleaded gasoline typically has an octane rating of 85. You'll often notice buttons for gasoline with higher octane ratings, including one labeled "Premium" with an octane rating in the 90s. Premium gasoline can withstand more excellent compression before combustion, making it essential for some Subaru models like the WRX and BRZ, which have higher compression ratios. Using regular unleaded gas in these cars could lead to premature combustion and potential engine damage. However, if your Subaru doesn't require premium gasoline, using it won't offer any benefits as it lacks unique qualities or added detergents. Note that the minimum octane rating in most states is 87, but in high-altitude areas like Utah and Colorado, you'll often find 85-octane gasoline.

Most gasoline in the United States contains ethanol, a biofuel made from plants like corn and sugarcane, aimed at reducing environmental impact. However, many engines aren't designed to handle high ethanol concentrations, so regular unleaded gas typically contains up to 10% ethanol. E15 gasoline contains 15% ethanol, and while gas stations may claim it's safe for cars manufactured in 2002 or later, Subaru only recently approved its use in some models. Using E15 on older Subaru models could void the warranty.

E85 gasoline contains a whopping 85% ethanol, making it quite different from E15. While some Subarus manufactured since 2018 can handle E15, the same can't be said for E85. This fuel is intended for FlexFuel vehicles with particular engines. Using E85 in your Subaru by mistake may result in reduced engine performance and the illumination of the check engine light. While a single tank of E85 in a non-FlexFuel car likely won't cause long-term damage, it's best to double-check before refueling your Subaru.

Learn More About Your Subaru

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