If regular fuel is good, then premium fuel must be better – right? Not necessarily for most vehicles. Going to that more expensive stuff may provide no benefit at all. You won’t get more power, better mileage or a cleaner exhaust if the engine was developed to run on a lesser grade.
As is always the case- follow the manufacturer’s recommendations. It developed the engine, tested it for millions of miles under a range of ambient conditions and loads. It has ensured it will remain problem free if operated under guidelines spelled out in the owner’s manual. It is also the one who will pay for damage or issues if something goes wrong.
The American Automobile Association (AAA) says using higher than recommended octane fuel “provides no increase in fuel economy, horsepower or a reduction in emissions.” In a recent report, the AAA said more than 16 million American drivers used premium fuel at least once a month, even though their vehicles required only regular grade gasoline.
Putting a number on it, the AAA says the waste amounted to $2.1 billion
Giving your ride a dose of the “good stuff” may have some benefits in terms of the additives in higher-grade fuels. Shell, for example, puts more detergents in its premium gas. But higher-grade fuel does not mean better performance or mileage.
The reverse is true if the manufacturer recommends premium fuel. That engine will produce reduced power and mileage if lower grade fuel is used. It has been calibrated for maximum performance on premium and will accommodate lesser grades, but does so by electronically dialling back some properties to prevent damage to the engine.
Most pumps display the octane rating of the various Grades of gasoline. It typically comes in three grades: Regular, 87 octane; midgrade, 89 and premium 91 to 93. The higher the octane number, the more resistant the fuel is to detonation or damage.. That is why running an engine recommended for premium fuel may be a problem and why modern electronics have allowed engineers to “de-tune” the engine automatically if lower grade fuel is used.
But it also explains why using a higher grade than recommended is unnecessary.
Your manual may say that premium fuel is “recommended”. That does not mean it is required, rather that the engine may perform slightly better on higher-grade fuel, but will get along just fine with regular. Consumer Reports conducted tests on vehicles where premium fuel was “recommended” It found no improvement in performance or mileage when compared with regular fuel.
If you have extra money burning a hole in the bottom of your pocket or purse, there are more rewarding ways of spending it, than adding to oil company profits.