With increased awareness about air pollution and also to ensure better maintenance of the automobiles, a number of rules have been bought into. Amongst these, an important one is in regards to the octane number of the fuel. It has been ruled that higher the octane rating of the fuel, the better is it suited for the car and the environmental conditions as well.
In order to denote the octane number, quite a few ratings are in vogue and the most common among them is the RON or the Research Octane Number and fuels with a higher RON are deemed more fit for present day cars.
Where does all this come from?
Well, initially the considerations about the RON started from the effects that a lower octane contained fuel had on an engine. According to the mechanism of petrol engines, both the fuel and the air are ignited with sparks plugs. As most present day cars that offer high performance come with higher compressibility ratios too, so it’s needed that the fuel can withstand a higher compression and reach the ignition point intact.
And this is exactly what the octane number takes care of. So higher the RON, the better is the ability of the fuel to withstand high compression without breaking off itself and causing knocking within the car engines. This enhances the life of the engine and hence, the car. This is important from the environmental perspective too. If a fuel has a better compressibility capacity, it will not transform into gas at an earlier state and thus, significantly reduce the emissions.
The difference between RON 91 and RON 95
As already explained, the basic difference is in the octane rating of the two fuel types. While one has a rating of 91, the other stands at 95. And here a 95 is always better than a 91, unlike the usual ranking system. Fuels that come with a RON 95 is evidently better than one that measures just 91 on the RON scale.
As such a RON 95 fuel can give a better performance as a fuel and enhance the performance and longevity of the engine and at the same time it is more ideal for the environment as it gives off lesser emissions as compared to RON 91.
As an extended benefit, RON 95 can give you a gain on the fuel economy. This is because, as the RON 95 can be compressed to a higher level than the RON 91, so the chances of the fuel being converted into gaseous substances are comparatively lesser and so more amount of the fuel is actually used in propelling the car than creating pollution. This increases the number of kilometers that the car can run on 1 unit of the fuel, thereby reducing the total expenditure.
However, this monetary profit is not usually retained as RON 95 fuels cost more than RON 91 fuels and it may happen so that you save less as fuel economy and spend more as fuel price.
So before you actually choose, do make sure what would be good for you and your car as well.