Planning to change fuel 95 octane to 97 or 100?

**bail** · January 20th, 2016 05:22 PM

Ive been experiencing engine knock recently and im planning to get a higher octane fuel. Im currently using premium gas with 95 octane fuel. Should i get the shell vnitro racing 97 octane or the petronblaze 100 octane?

**1D4LV** · January 20th, 2016 05:48 PM

Originally Posted by bail

Ive been experiencing engine knock recently and im planning to get a higher octane fuel. Im currently using premium gas with 95 octane fuel. Should i get the shell vnitro racing 97 octane or the petronblaze 100 octane?

hmmmm. i think the 95 octane would be sufficient. there may be other issues like:

a. wrong air-fuel ratio
b. engine cylinder pressure may be high.
c. manifold pressure may be high due to big throttle opening.
d. high engine load
e. ignition timing.

what would be the brand/make/model of your car?
but if you want, you can try the 97 octane first, but still i feel the octane would be too high. if it goes out at that octane level, then its good, but due to the reasons i stated above, it may again go out in the future.

**yebo** · January 20th, 2016 07:06 PM

first, find out the reason it is knocking.

1. pa-check mo muna ignition timing mo.
2. is there a knock sensor? it is possible the knock sensor has malfunctioned.
3. is the engine clean, no high carbon deposits inside the cylinders, spark plugs clean and in good condition? are there any issues that may cause pre-ignition?

imho, if there is a problem with the engine then changing the octane rating of your fuel will not solve your problem. go to the cause.

**granro01** · January 22nd, 2016 10:26 AM

Originally Posted by bail

Ive been experiencing engine knock recently and im planning to get a higher octane fuel. Im currently using premium gas with 95 octane fuel. Should i get the shell vnitro racing 97 octane or the petronblaze 100 octane?

If you have been using 95 octane for years and just recently experiencing a knock then there is a serious problem other than your fuel and changing it to higher octane will not solve your problem else worsen it in the long run. Have an experienced mechanic take a look at the problem.

**XTO** · January 22nd, 2016 11:23 AM

Change the fuel filter first and spark plugs.

**dr. d** · January 22nd, 2016 12:38 PM

i agree.
perhaps you should have the engine seen first, and possibly, get it tuned up.
the problem may just go away after that tune-up, without having to change your fuel grade.
who knows, you might just be able to use 91 octane fuel after that tune-up!.

**ivo3** · February 15th, 2016 12:15 PM

can hot air cause engine knock?

**bail** · February 16th, 2016 03:46 PM

The engine knock has lessen after i changed my fuel to 97 or 100 octane. Sometimes i can still hear a few knocks but not unlike before where the knock is severe

**1D4LV** · February 16th, 2016 04:27 PM

Originally Posted by bail

The engine knock has lessen after i changed my fuel to 97 or 100 octane. Sometimes i can still hear a few knocks but not unlike before where the knock is severe

but. the knocking is still there. so hindi dun ang problema.

**bail** · February 22nd, 2016 03:36 AM

Im now using 100 octane by petron blaze. So far wala na yung knocking and i can really feel na much smoother na ang driving experience ko. So what does this means?