Is cheap gas like unleaded 88 and flex fuel more expensive in the long run? - Saving You Money (2024)

CLEVELAND, Ohio — Unleaded 88 is a cheaper way to fill up your tank. 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.

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The short answer is this: If it’s 20 cents cheaper than unleaded 87, it will probably save you money in the long run, even with fuel economy factored in. But prices at the pump aren’t that consistent.

And as for unleaded 88′s significantly cheaper cousin, flex fuel (E85), it may actually hurt your wallet — even if your vehicle is designed for it. The science behind why is complex. But it needs to be about 90 cents cheaper per gallon to guarantee savings.

But of course, your mileage may vary. Here’s why:

The science behind gas

Before we talk about money, let’s define a few key terms: octane, ethanol and “regular.”

Most gas stations offer three kinds of gasoline; unleaded 87 (regular), unleaded 89 (mid-grade) and unleaded 91 (premium). The 87, 89, and 91 reference the octane rating — which measures how much heat and pressure a fuel can withstand before it ignites.

Many vehicles are designed for unleaded 87 — granting it the title of regular. Higher-end vehicles are designed for higher-octane fuel.

Ethanol is a kind of alcohol, usually made from corn, that’s used as fuel.

Unleaded 87, 89 and 91 are up to 10% ethanol. Unleaded 88 is 15% ethanol, which is why it’s cheaper. Flex fuel has anywhere from 51% to 83% ethanol depending on the region and time of year.

For this reason, unleaded 88 is sometimes called E15. And flex fuel is called E85 — and some pumps even call it 105 — because it has a ton of octane.

Why does all of this matter? Well, these cheap fuels are a double-edged sword.

Ethanol has just two-thirds the energy of pure gasoline. The more ethanol in your fuel, the less energy it has per gallon. On the flip side, fuels with a higher-octane rating burn more efficiently. Both affect fuel economy.

Each vehicle handles these changes differently. How different depends on who you ask.

Fueleconomy.gov, which is run by U.S. Department of Energy, says unleaded 88/E15 will get 3% to 4% less miles per gallon than regular unleaded 87 gasoline.

Flex fuel can only be used in vehicles designed for it — called flex-fuel vehicles or FFVS — but even these vehicles get roughly 15% to 27% fewer miles per gallon using flex fuel compared to unleaded 87.

However, averages are not absolute — and are up to debate.

The Renewable Fuels Association, a trade industry for America’s ethanol industry, says unleaded 88 is just 1.7% less efficient on average.

And tests done in California show that newer vehicles were only 1.3% less efficient when using unleaded 88 rather than unleaded 87. The test looked at 20 newer vehicles and included everything from a 2018 Honda Civic to a 2018 Chevy Suburban.

Robert White, the RFA’s vice president of industry relations, pointed out that it can vary widely.

A 2016 Mazda3 was 5.2% less efficient, while the 2017 Ford F-150 saw no change. The 2018 Honda Fit and 2020 Jeep Compass were both more efficient on the cheaper, higher ethanol fuel.

Flex fuel varies even more. According to the RFA’s website, flex fuel/E85 is 22.7% less efficient on average. But White’s own vehicle, a Ford Escape plug-in hybrid, is only 3% less efficient.

This makes the math shaky at best.

Unleaded 88: Does it save you money?

If we skip science and look at math, will using unleaded 88 or flex fuel save you money? Yes, if the discount is higher than the decrease in miles per gallon.

For simple math, our vehicle gets 25 mpg and we drive 15,000 miles each year.

Let’s also use the U.S. government’s data and say unleaded 88 is 3.5% less efficient, while flex fuel is 21% less efficient.

For a real-world example, I used recent gasbuddy.com prices from a Sheetz in Strongsville. Unleaded was $3.69. Unleaded 88/E15 was $3.15 and flex fuel/E85 was $3.09.

Using unleaded 88 would save this driver $255. But using flex fuel would cost them an extra $133. That’s over a whole year.

A better way to look at this might be every 500 miles.

Using regular gasoline, driving 500 miles would cost $73.80. Using unleaded 88 would cost $65.28. And using flex fuel would cost $78.23.

But change the prices and the results change. At a Sheetz in Seville, according to GasBuddy on the same day, unleaded 87 was just $3.29, unleaded 88 was $3.19 and flex fuel was $2.69.

At those prices, the “cheaper” unleaded 88 costs you $9.42 more a year — or 31 cents more every 500 miles — than unleaded 87. Flex fuel is still a money loser at this station — but less so.

Now the RFA has it’s own online calculator, found at e85prices.com/calculator. According to it, unleaded 88 saves money in both scenarios — but flex fuel is still a losing proposition.

The difference between unleaded 87 and unleaded 88 could be less than a nickel or a couple of quarters on any given day. And the savings are based on percentages, not cents.

If unleaded 87 is at $4 and unleaded 88 at $3.90, you lose money with 88. If it’s $2.50 versus $2.40, you save money.

Should you keep a calculator in your glovebox? No.

Patrick De Hann, head of petroleum analysis for Gas Buddy, said 20 cents is a good rule of thumb. If unleaded 88 is 20 cents cheaper than regular, he buys it. If it’s 4 or 5 cents cheaper, he gets regular.

My math says this rule of thumb generally works out in most scenarios. Your vehicle may be different.

White, of the RFA, would save $10.34 every 500 miles using flex fuel at the Sheetz in Seville. Because he tracks his vehicle’s MPG, he knows flex fuel is always a good bet for him.

Can you use unleaded 88, or will ethanol kill your engine?

Many people say ethanol will damage your engine, and some drivers even seek out fuel that’s more expensive but has no ethanol.

De Hann said the problem with ethanol is the same problem with alcohol you drink, it makes you dehydrated and it can dry out rubber — specifically the rubber hoses in your vehicle.

Many vehicles now use a synthetic rubber that’s more durable, helping it stand up to ethanol. Again, most gas sold today is up to 10% ethanol.

In a classic car from the 1970s or 1980s, more ethanol may be a bad idea. In a vehicle made after 2010, De Hann said your vehicle is most likely fine to use unleaded 88.

The U.S. EPA said unleaded 88 can be used in most vehicles built after 2001. De Hann said it’s a good idea to check your vehicle’s manual.

If you’re interested in trying it, many Sheetz gas stations carry it. And others are slowly catching on.

Now boats, motorcycles and gas-powered tools are a different story. There’s a debate about whether the problem is ethanol, or if it’s people who don’t take care of tools with products like fuel stabilizer. It’s a debate I’m not qualified to participate in — but it’s generally recommended to use an ethanol-free fuel like REC-90. It’s also sold in cans at home centers.

With flex fuel, you need to make sure that your vehicle is designed to use it.

According to the EPA, only vehicles that are designed to use E85 can use it for fuel. You can look up if your vehicle can use E85 at pearsonfuels.com/flex-fuel-car-check/.

Flex fuel vehicles will normally have a yellow gas cap or a badge that says “flex fuel.” Vehicles that can’t use it might have an E85 prohibition sign (the circle with the cross through it.)

This isn’t to say that flex fuel is pointless. Some drivers use E85 for performance, citing its high-octane rating. There’s also environmental arguments. It burns cleaner and is made of corn instead of fossil fuels. But whether that corn farming is sustainable is a debate, and I only cover money debates.

Saving You Money is cleveland.com and The Plain Dealer’s column about saving money. We want to know how we can help you save money. Send your questions and comments to smcdonnell@cleveland.com.

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