Despite the change in fuel labeling, no one calls 95 gasoline E5 or 98 gasoline E10. For now everyone maintains the “old-fashioned” name and we still hear many comments (this week, without going further) of the type “my car runs much better with 98 gasoline” or even “it makes up for the difference in price because my car consumes much less than with 95 gasoline.”
Is that true or does the fact of paying more make us run more (and give us the sensation that the car runs more) or do we hold back more with the accelerator, because of having paid more and that is why the car consumes less? You will also hear that, disregarding the difference in cost, you will obtain better performance and theoretically greater mechanical durability, since the fuel is better at a chemical level. All this is very debatable.
The most notable difference that we can all certify when we approach a service station is the price.
There is around a 14% extra costwhich is a very high amount. Is it justified? Is it worth it? Well, as a good Galician, I will answer that it depends. It is better to inform yourself about the benefits of using one fuel over another and if it can compensate you.
Difference between 95 and 98 gasoline
There is a 3 octane difference between one fuel and another. When we talk about octane rating referring to a fuel we are referring to its self-detonation resistanceto autoignition, which is greater in 98 octane gasoline.
When the gasoline reaches the combustion chamber, where it is mixed with air at a very high pressure, in a very short time (compression phase), it must be ignited, using the spark from the spark plug, at the precise moment. 98 gasoline is better for that because of its higher octane, but then each mechanism has been thought of differently, with different compression ratioswhich is a number that measures the volume ratio in which the air and fuel mixture has been compressed in the engine. This figure indicates the degree of use of the energy of the fuel.
If you hear about a very high compression engine (always referring to gasoline engines), it is very likely that you should use 98 octane gasoline. Using one with a lower octane rating could cause it to explode prematurely and combustion would not be adequate.
Does 95 gasoline contaminate more?
Gasoline has sulfura dangerous component for the environment. Its percentage is higher in 95 gasoline, which is why it is currently the minimum rate allowed in Europe. It is the most used… due to its price, in addition to having other advantages, such as facilitating cold starting or its lower weight, as it is less dense.
In 2013, the European Union approved the Directive 98/70/ECwhich seeks to increase the quality of gasoline and diesel. So it was decided to ban 95 octane gasoline. Yes, a fuel that 3.5 million vehicles in Spain use… and that have no other alternative. There have been several extensions. The first extended its sale until 2016, the second until December 31, 2018… and the third until the end of 2019, just one more year. It remains to be seen if this grace period is extended.
What is the best type of gasoline for the car?
To know which gasoline is best for your car, you must read the car manual. A team of engineers has developed the engine for a specific fuel. Our advice is that, unless the manufacturer expressly recommends 98 octane gasoline or prohibits 95 octane gasoline (which occurred in the old FSI engines), the most sensible and economical thing to do is to use 95 octane gasoline.
What if I make a mistake when refueling?
Normally all cars with gasoline engines accept both types of fuel, although the manufacturer always recommends one or the other depending on the characteristics of the engine. all cars manufactured before the year 2000 They use 95 gasoline, and those sold after that date can use 95 or 98 gasoline either… or just 98 gasoline. Knowing this:
- All the cars that They recommend 95 gasoline They can take 98 without the mechanics suffering any damage (what you can notice is that you lose some power although the difference, unless you drive a sports car, is almost negligible).
- Now, if your car recommends 98 gasoline (it happens in high-performance models, such as sports cars), we do not advise you to add 95. In this case, not only will the power decrease, but it is possible that you will use even more fuel. You will also make the mechanics suffer unnecessarily… and in a high-priced car.
Of course, it’s better not to mix them:
Is it possible to notice any changes? Yes, but especially in naturally aspirated engines or those with high performance, thanks to high compression ratios. That is why owners of old cars (when the turbo was not popular) claim that it is noticeable in their cars. But in current cars, except high-performance ones, in which the manufacturer advises using 95 octane gasoline, you will not notice a difference when using 98 octane gasoline.
