I’ve passed by Refuel, the new gas station in Industrial Park, several times and noticed the lower prices they offer on their gas. But is the fuel OK to use in all types of cars? I’ve checked their website and cannot find any information about that.

Cayman National Bank

Ask Auntie sponsor

Auntie’s answer: I have also been intrigued by the cheaper prices they offer and have wondered about using that gas in my car. I contacted the fuel experts at the Utility Regulation and Competition Office, known as OfReg, and the helpful folks at the Fuels Inspectorate offered lots of useful information in answer to your question.

But first I want to say that your comment about the Refuel website has already made a difference. An OfReg fuels official explained, “Given that our enhanced regime has only come into force just over a year ago, as part of enforcing compliance, we also continue to remind importers to ensure they are meeting their various obligations under the law.” And he added that your question was “useful for us in following up with the permit holder/licensee in this regard”. The regulator is requiring that Refuel update information on the grades of gas it offers as well as include other relevant information on their website.

Now, on the issue of whether the gas sold at Refuel is suitable for every car, the fuels official explained that the majority of cars using gasoline manufactured after 1986 can use fuel containing 10% ethanol, or E10, which Refuel sells. “However, the only true way to know if a vehicle can take E10 is to verify with the vehicle’s owner manual,” he added, explaining that almost all the gasoline sold in the US contains at least 10% ethanol by volume as required by the Environmental Protection Agency.

“Pure (100%) ethanol contains about one-third less energy than gasoline, so vehicles will typically go 3% to 4% fewer miles per gallon on an E10 blend,” he said. “Compared with conventional gasoline, ethanol-blended fuels contain more oxygen and are thus more likely to achieve complete combustion that lowers certain harmful emissions.”

More information on fuels in Cayman is also on the way: “In due course, OfReg will also have pertinent information on the various types of fuels available in Cayman to supplement information by the various importers under the Fuels Standards Regime.”

And even though you didn’t ask, since Refuel offers options (87, 90 and 93 octane) not available at other gas stations (89 and 93 octane), I wanted to clarify how they compare.

Those octane numbers are actually AKI (anti-knock index) but all gas stations use that representation so they can be compared. The best fuel for your car depends on what the manufacturer recommends. But an official advised that if 87 AKI is recommended for your car and you have been using 89 AKI, the 87 AKI from Refuel would be fine, if the vehicle’s manufacturer says it can handle ethanol. If 89 AKI is recommended then Refuel’s 90 AKI would be the “wiser choice” between 90 and 87.

And, finally, here is how the various fuel choices stack up: 87-89 is regular grade, 90-92 is mid-grade, and 93 and above is premium.

For more information on gas options, you can take a look at this previous column on octane ratings.