Agreed but your argument is valid only if the quality of regular fuel is good enough. The problem is that the regular fuel available these days is of pathetic quality... especially since after the imposition of RON-92 grade.
My gli used to give 13.5kmpl within city some 2 yrs ago. Then, drastically its average fell to 9-10kmpl.
I tried every known solution from fuel pump servicing to changing plugs, coils and even injectors but with zero results.
After exhausting all the known juggars by local mechanics, I went to Toyota Capital Motors Isb and you know what did the head mechanic say? He said all of those cars that were there for minor tune ups were there with the exact same complain. He simply advised me to re-install the original coils + injectors (which I fortunately had kept with me) and use hi-octane as it was less likely to be adultered. He didn't even charge me anythingrather advised me to get this work done by my own mechanic.
I followed his instructions and now my car is again giving 13+kmpl within city which it used to give with RON-88 fuel.
My assumption is that oil companies are using some juggar to increase the RON number of normal fuel which is seriously affecting cars' performance
