Which octane is best? 87? 89? 91? Other?
 

When at the gas pump, does it really matter which octane I'm using? 87, 89, or 91 octane? I think 87 is recommended for our cars but I'm using 89. Once in a while 91 Just something i was pondering on....
;peace;

89 is ethanol... i personally believe that stuff ruins engines... i could be wrong. but in my experience... its burns hotter... its 10% CORN!
87 isn't bad. it doesn't have corn mixed into it....
91/92/93 depending on the gas station.... seems to give a little more punch to the little 4 banger, but maybe thats just a phsycological thing that i trick myself into believing... and most oil companies add detergents to it to help keep your fuel system clean, at least they CLAIM to.... who knows these days.... OPEC rules all of our lives whether we like it or not... lol

totally wrong.

ALWAYS use the lowest octane rating you can get away with without pinging or knocking.


Octane has NOTHING to do with performance. It's the unit to measure a fuels resistance to pre-detonation (or pinging).

The higher the octane you use the harder it is for your car to ignite the fuel and it throws off ignition timing. Stick with what the label says.

^^ Listen to the man, he knows his s#it.

Higher octane gas burns slower than low octane. Use the lowest you can get away with before your motor begins to "ping". In my P5, it's 87. In the MSP, 89. In the FD with all its mods, it's the $3.75 a gallon stuff. :(

Unless your pinging/detonating, then it's smarter to save your money on something worthwhile....LIKE PINK UNDERCAR NEONS!! :rofl:

pink undercar neons roflol! :yelrotflm

jeezus thank you Matty...I thought I was going to blow a gasket at first with all this misinformation

no prob Mike.

It's too bad that only the high octane fuels have the additives though. It's nice to have pre-mixed gasline antifreeze or injector cleaner in the gas for the few cents more.

cheveron's 'techron' addittive (i've been told its one of, if not the best) is in all 3 grades of gas, at least down here in Tejas.

Yeh, our 'Petro-Canada' (our Chevron I believe) only puts the 'tactrol' additive (injector cleaner) in the 91.

They put gasline antifreeze in all levels though.

probably necessary but a shame. Watered-down gas sucks.

Definetely necessary around here...

Holy shit, you couldn't be more off.

All grades of gasoline sold in the US are up to 10% ethanol- at least anything you buy at a gas station.

Higher octane is generally for higher compression engines. A naturally aspirated Mazda3 isn't high performance by any means. Using premium gas is just pissing money away.

Unless your driving a MS3, premium is not required. Also Mazda does not recommend adding any other outside additives to your fuel as well as oil.

Not all gasoline sold in the US has ethonal in it tho.

Until recently all gasoline sold at shell stations was pure gasoline.
Now I believe they only put ethanol in regular unleaded.

Some BP stations around me have pure gasoline. I hate ethanol. I had a 1993 honda civic ex coupe before my mazda 3 and they screwed up the winter mix of gasoline and broke all 4 of my fuel injectors.

I hope ethanol just goes away ... is it really better for the environment when it takes more energy to produce ethanol then it does gasoline. We should be concentrating on other alternative fuel sources.