95 gasoline or 98 gasoline? Many times, when we drive a car with a powerful or high-displacement engine that is compatible with both types of fuel, we are asked the question of which one will be more suitable for our car. We are going to see what the main differences are between one fuel and another, but first, remember that, although we continue to call these fuels 95 gasoline and 98 gasoline, their “official” names according to European legislation are E5 gasoline, 95 , and E10 gasoline, the 98.
The main difference between the two fuels is, of course, the octane number, which is the number that gives name to both types of gasoline. Octane is the fuel’s octane number, a numerical indicator that indicates the fuel’s resistance to detonation when compressed inside cylinders. The higher the octane number, the greater the compression capacity of the fuel and, therefore, there is less chance of it exploding before the spark is generated that ignites it.
Being a fuel with higher compression capacity, the explosion generated by 98 octane gasoline when receiving the spark from the spark plug is more energetic and that means that its performance is superior when it comes to generating engine power. For this reason, the use of 98-octane gasoline is usually recommended in high-power engines whenever you want to achieve the performance advertised by the manufacturer. In other words; in a sports car with the engine pushed to the limit, performance will be better if 98 octane gasoline is used.
Another difference is the amount of sulfur contained in the gasoline, which is higher in 95 octane. That makes the explosion of 98 gasoline cleaner and less aggressive for the moving parts of the engine despite the fact that it is produced with compression. For this reason, in addition to greater performance, 98 octane gasoline offers greater protection for the engine when higher performance is required.
Finally, there is another important difference and this is none other than the sale price. Right now (February 2022), the average for 95 octane unleaded gasoline is between 1,491 and 1,632 euros, while that of 98 is between 1,621 and 1,762. The difference, therefore, is notable, although it should be noted that since there is no low cost gasoline (more information on this type of fuel) with 98 octane, the average for this last fuel is higher. The difference is between 10 and 20 cents per liter, depending on the gas station.
What type of gasoline should I use in my car?
In this case, the answer is simple: the one recommended by the manufacturer. Each brand develops its engines with a type of gasoline in mind (for example, in engines developed for the use of 98, the compression ratio is usually higher). In engines prepared to use 98, it is best to refuel with 98. The engine will perform better and we will increase reliability. If we put 95 gasoline in a car that advises 98 we can detect a certain lack of power and it is even possible that consumption increases, so what we can save at the pump we can lose in use.
When the brand announces that the vehicle can use both fuels indistinctly and except if it is a high-performance car, the logical thing is to use 95-octane gasoline since the differences in performance will be negligible and the price difference in this case does it will be impossible to compensate by other means. In any case, mixing both fuels, by mistake or by mistake, does not cause any type of damage as long as it is not done repeatedly.
