Good Day! Thanks for your column in Top Gear Philippines and to Top Gear itself. You are educating noob car owners like me a lot.
I would like to ask if it's ok to load up my 19-year old car with a high-octane gasoline like Petron Blaze (96 octane rating) or Shell V-Power (97 octane rating). I'm currently using Petron XCS with 95 octane rating. Will my car benefit (except my wallet) if I load her up with these high-octane gasolines?
Thank you and best regards,
Octane rating refers to anti-knocking or auto ignition properties of fuel usually gasoline in spark fired engines, or engines with spark plugs. The higher the number, the more resistant it is and, contrary to popular belief, it burns slower or in a more controlled manner than a fuel with a lower octane rating.
Octane ratings of fuels are measured in a test engine using a mixture of iso-octane and heptane that has the same anti-knock characteristic as the fuel being rated. The amount of iso-octane by volume, expressed as a percentage, used would be the octane rating of the fuel. In the case of a 95 Octane rated fuel, it would have the same anti-knock properties of 95% iso-octane and 5% heptane mixture. Now this does not mean that the gas or fuel uses these two components but instead means that the fuel has the same anti knock properties or same amount of resistance to detonation only.
Whether your car will benefit from running higher octane or not is a matter of tuning.
If your car has no way to take advantage of the increased detonation resistance (i.e. not tuned for the better fuel quality) then it won't benefit you in any way at all. However, if your car has been tuned to take advantage of the better fuel quality, then definitely going with a higher octane will benefit your car both in power and fuel economy.
If your car is 19 years old, it most likely still has a distributor. Therefore, you should be able to take advantage of the higher octane fuel. A quick way to check if you can benefit from using a higher octane fuel is to fill up with it and see if your getting better fuel economy. If you don't get better fuel economy, then your better off sticking with the cheapest fuel that gets you the best mileage.