Many of us will remember the days when you could stop at a gas station, throw in $5 of 87 octane, and hit the road for miles without worry. Those days are over and have been for quite some time, as Energy.gov’s recent Fact of the Week showed that automakers have recommended premium fuel for most light-duty vehicles since 2018.
More than half of all light-duty vehicles come with a premium fuel recommendation, a significant increase from the 6.5 percent of vehicles needing premium back in 1985. That growth is due in part to automakers’ move to smaller turbocharged engines and higher compression requiring higher octane.
While it’s still possible to buy a car that doesn’t require high-test fuel, the number of available models has fallen pretty consistently over the past two decades. Vehicles requiring midgrade gas weren’t broken out of the numbers until 2011, but the category has represented a tiny number of available models since.
Octane ratings measure a fuel’s ability to stop “pinging” or “knocking.” While there are outliers, such as racing fuel, most gas stations in the United States offer three octane ratings that range from 87 for regular fuel to 93-94 octane for premium. The higher the octane rating, the more capable the fuel is of resisting knocking at higher compression levels, allowing automakers to extract more power from smaller, more fuel-efficient turbocharged engines.
While it’s always a good idea to follow your vehicle manufacturer’s recommendations, there may be times when premium fuel is unavailable. Newer vehicles’ advanced engine control systems can often adjust operations to accommodate lower-octane fuels, but they may suffer a fuel economy or power hit along the way. At the same time, using premium fuel in a vehicle not designed to take advantage of it can yield little to no benefit and costs way more in the process.
