There are kinds of advice people rarely hear about gasoline. Here’s another important point: pouring fuel with an octane rating that isn’t suggested for a given engine can be a poor choice for your wallet; it doesn’t necessarily harm the engine, but it doesn’t bring any real benefit either.
On the fuel door, a specific octane is listed as recommended, while another option is shown in parentheses. The bracketed option is meant only for times when the preferred fuel is unavailable at the station. It isn’t intended for long-term use.
Expert opinion
Mikhail Kolodochkin, columnist for “Behind the Wheel,” shares his perspective:
Using gasoline with an octane number higher than what the manufacturer specifies may not damage the engine, but it simply costs more money without providing additional advantages. In very hot conditions, higher octane can reduce the chance of knocking, which is the only practical benefit for some drivers. So, there are scenarios where it makes sense to opt for higher octane, but those moments are rare and situational.
Conversely, relying on gasoline with a lower octane rating over time can create problems. Short-term use of octane 92 instead of the recommended 95 may be tolerated if driving behavior stays smooth and avoids rapid acceleration or heavy loads. Engines are designed with a margin to account for small deviations, but that margin diminishes with regular low-octane fueling.
Constantly topping up with lower octane fuel erodes that margin, and a single day when the fuel is 90 octane instead of 92 or 95 can threaten the engine’s balance if the deviation is larger than about five octane numbers. The risk increases with heat, load, and aggressive driving.
In hot weather, using 98 octane gasoline in a car built for 95 can be sensible for some drivers, but otherwise it is a waste of money. Occasional use of fuels with octane ratings below the recommended level is possible, yet it should not become a habit if resilience and performance are priorities.
Further details are provided in the material titled 5 common misconceptions about gasoline, which addresses dangerous myths and practical guidance.
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