A lot of car owners are needlessly nervous about their vehicles. The check engine light comes on, and they freak out. No, your car isn’t going to explode. It’s usually just a glitch in the emissions system.
Another source of owners preoccupation is fuel type. In the US, you have three main options: regular 87 octane, plus 89 octane, and premium 92/3 octane (sometimes called “super” or branded with names like “V-Power”).
“Octane” is part of the complex chemistry that makes up modern gasoline, but for the purposes of fuel grades, it boils down to how the engine will treat a phenomenon known as “knocking.”
There’s an elaborate explanation for why knock — that rattling an engine might sometimes make — occurs, but the short version is as follows.
Your standard internal-combustion engine is based on the principle of a relatively precisely controlled series of explosions: fuel and air are mixed in the combustion chambers or cylinders, the mix is set off by a spark, and BOOM! compression occurs, creating mechanical momentum which the vehicle then transfers to the drive axle through a transmission. Vroom!
When this process gets out of whack, knock can happen. Premium fuel is supposed to alleviate that knock, and additionally enhance the performance of certain types of cars.
The usual recommendation is that you follow the manufacturer’s guidance for fuel type and use premium, which costs notably more than regular, if the owner’s manual says to. Sometimes, higher octane fuel might be recommended.
But you really don’t need to go down that route.
Most engines in most cars can, through computer monitoring, determine what kind of fuel they’re burning and adjust accordingly. So you gain nothing by paying more for gas. And don’t buy that business about premium being formulated to keep your engine cleaner. Your engine was designed to run Fuel X and to be just fine.
Some cars do need premium, but they’re mostly luxury vehicles whose owners expect higher levels of performance. They have engines that run on higher compression, and the additional octane rating enables these motors to operate without knocking. Edmunds.com has put together a list of 2011-2016 models that should be run on premium, and you won’t find a whole lof of surprises there. These are the types of vehicles we often test at Business Insider, and when refuelling, we always go with premium.
But if you’re a typical car owner driving a typical car (or SUV), you can skip plus and premium and save yourself a few bucks.
Beyond all this, if you do buy premium when it isn’t recommended for your vehicle, you could be one of the many Americans who collectively wasted $2.1 billion a year in 2016, according to a new report from AAA.