Issue February 2017 - Octane (2024)

FAQs

What happens if I put 88 instead of 87? ›

Vehicles that are not listed as being able to run 88-octane could see long-term engine damage including a higher likelihood of seeing fluids leaking. Engines not equipped with newer equipment to handle 88-octane could potentially overheat. With the big sale this weekend, that difference may be hard to ignore for some.

If you're still filling up at the pump and realize your mistake, you can top off the rest of your tank with regular gas. Your check engine light will probably turn on, but it will turn off once the fuel starts to burn off.

Yes, drivers can mix the two types of fuel. The combined gas types will result in an octane level somewhere in the middle — something the vehicle “will survive,” according to The Drive.

Regular gas with an 87 octane level is suitable for most engines, while some high-output engines require premium gas with higher octane levels (91-94). Engines designed for regular-octane gas gain little to no benefit from using high-octane fuel.

Unleaded 88 is usually noticeably cheaper than traditional gasoline because ethanol is a less expensive fuel source than crude oil. And, because up to 15% of Unleaded 88 is made of the biofuel ethanol, it uses less crude oil per gallon than traditional gasoline.

But because it has more ethanol than regular gas, it's less fuel efficient. Will buying it actually save you money? Kinda, sort of and maybe are the best answers. The extra ethanol in unleaded 88 probably won't damage your engine — but your vehicle will likely get less miles per gallon.

If you have an old car that needs high-octane fuel, running 87 octane might make it start knocking before you can leave the gas station. It will sound bad and perform poorly, but even so, will probably escape permanent damage.

If a manufacturer recommends premium gas, you can still use 87-octane, but it might cause problems to your car's engine. If you want to use regular gas in a premium car, many gas stations sell octane boosters you can pour into the tank, which will prevent any misfires. Different fuel grades do not burn the same.

Unlike high-quality engine oil, premium gasoline doesn't make a car accelerate faster, run cleaner, or become more efficient.

There's nothing wrong with mixing premium and regular gas in the same tank. In fact, this is how midgrade gas is formulated at the station. Rather than drawing from a separate storage tank for each octane rating, gas pumps actively mix high-octane fuel with lower-octane fuel to create midgrade gas.

What happens if I put E85 instead of 87? ›

This fuel's chemical make-up is derived mostly from biomass materials such as corn. If you accidentally put E85 fuel in a car built for regular petroleum-based gasoline, chances are your check engine light will come on. And while that's never a good feeling, a one-time mistake shouldn't cause engine damage.

You'll know you're filling up with the good stuff if you spot a small green sticker on the pump that says “TOP TIER Detergent Gasoline.” As of early 2022, the following stations sold Top Tier gasoline in the U.S.: 76, ARCO, Aloha, Beacon, Breakaway, CITGO, Cenex, Chevron, Conoco, Costco Wholesale, CountryMark, ...

Top-tier, name-brand stations like Shell, Exxon, Mobil, and Chevron hold themselves to higher standards when it comes to additives and how often they change the filters in their tanks. This leads to higher quality and fewer chances for problems to occur due to dirty or unregulated gasoline.

No, any fuel efficiency gained using premium fuel would stem from engine performance, not the gas itself. Buying premium gas won't have you visiting a gas station any less frequently, especially with a standard engine not designed to take advantage of premium gas.

There's nothing wrong with mixing premium and regular gas in the same tank. In fact, this is how midgrade gas is formulated at the station. Rather than drawing from a separate storage tank for each octane rating, gas pumps actively mix high-octane fuel with lower-octane fuel to create midgrade gas.

Once you've recognized the mistake, stop your car immediately to avoid additional damage. Then, it's a good idea to call for a tow and to get your system flushed by a trusted auto technician. In both cases, your fuel tank will need to be drained, and your fuel lines will require a thorough cleaning.

If your car requires premium to run smoothly, but you aren't able to find a station with premium gasoline, it won't hurt to top off with regular gasoline. You do want to avoid running on regular gasoline for extended periods of time.