Kizashi Club

Gas gets reformulated with passing seasons.
Geographic region dictates formula; different regions get different formulas.

My gas might be different from your gas.

I still run mostly Mobil premium.

i use Shell on my vehicles. 87 Oct on the stock ones, 91 on my civic (modded). If i need to, i will use other brands. Consistency is the key, as the ECU factors in the gas for performance.

For the reason stated, I would not use Mom & Pop gas or places that buy whatever gas they can get their hands on (heard Arco does this- not sure)

hotdog wrote:For the reason stated, I would not use Mom & Pop gas or places that buy whatever gas they can get their hands on (heard Arco does this- not sure)

Follow the gas truck around some day ... You will be surprised who gets what gas.

tc you are 100% correct.
And anything over your cars octane rating gets blown right out of the exhaust pipe. Ex: say you use 92 octane but your car calls for 87 octane. Well 5 octane get wasted since your car can't burn it.

jono6406 wrote:tc you are 100% correct.
And anything over your cars octane rating gets blown right out of the exhaust pipe. Ex: say you use 92 octane but your car calls for 87 octane. Well 5 octane get wasted since your car can't burn it.

Correct me if im wrong but your cars octane rating is its minimum recommended octane not maximum. I always use 95 when it's recommended 91. I definitely see improved fuel economy and nicer performance. I've never heard of "wasted octane".

Ok just looked into this more, seems to be a pretty common debate online. Sparked my curiosity now have you seen anything to prove it? I'm pretty curious about this. I recently went with s friend to get his car dino'd he swears by 91 and its recommended for his car but the dino guy recommended he used 98? Given his car is pretty heavily modded. Nothing too internal though.

Just a quick point - the fuel octane ratings between USA and Australia are different. USA use the MON rating and Australia RON - the MON number is significantly lower compared to the RON for the same octane level. (PS: I'm sure Google will explain it better than me!)

Higher octane does generally make a small difference, but whether it is actually benefiting your car is questionable. I don't believe the argument that extra octane is "wasted" as in it's not burned. I don't think selective octane combustion is even possible.
I use regular 87 octane fuel readily available in the US. I don't bother wasting my money on 89, 91, or whatever. If I had used them, it may make a performance difference, but it would not outweigh the financial cost nor is it actually benefiting the car in terms of maintenance, longevity, etc.
Some may argue that higher octane burns better and more completely, therefore the exhaust valves, etc. are in better shape, but I would like to see evidence of this in a car that called for regular. Every study I've read on the matter claims there is no benefit to higher oc gas in a car calling for regular in terms of these things.

I also usually pour Seafoam into my gas tank at every oil change. It's a petroleum cleaner type product that cleans out injectors, valves, etc. I've been using it for years on different cars with no issues. O2 sensor safe.

The only evidence I have seen is you get a watery/pasty build up in your cylinders and the water in ethanol doesn't burn. I just remembered that. Look on YouTube there used to be some videos. This happened to my last car after 4 years of using 91. Often didn't start properly and never ran too smoothly.

Since my car has sensors to detect various 'knock' inputs, higher octane allows for its computer-controlled systems to maximize timing and other parameters when I mash the go-pedal.
Ay?

Mash mash mash.....