Engine Gasoline Grades

Gasoline Grades

What is the real difference usage wise in the different grades of gas, besides the fact that high octane stuff burns better and gives better performance. I've heard 1ZZ-FE is designed to run on 87 oct, and I was running 93 oct on it, and I was advised not to do that, since there are some "issues" with that. What are these issues? Would really like to know and appreciate all help...

running higher octane in an engine which isnt designed for it basically speeds up the wear and tear on the engine. On Japanese engines, i've never really seen anything bad happen other than the engine may run more rich when you first turn on the engine on cold mornings. But I have heard of pistons going bad when running high octane at high rpms.

Even though premium is supposed to burn cleanly, its not the case in engines which aren't designed to burn it. The higher the octane, the slower it burns. Hence why it can utilize more O2 and create a more efficient burn. However, if run in a motor not designed for it, it will not burn cleanly and will leave behind residue, carbon deposits, or buildup.

I don't know if its safe to run 87 in a WRX. It would ping wouldn't it?

As I remember top gear and some other car shows, higher octane grade is more stable it prevents premature detonation due to heat and pressure, if you got more stable gas then you engine works better, generally higher octane gas gives you more power however when tested on 1.3L engine it has absolutely no effect, on a 2.0L it just added like 4Hp more (shell 98 octane) and on subaru WRX it actually made a 12Hp difference compared to 87 octane... for your normal city driving you can easily go with the cheaper 87 octane gas and you'll be fine.

WRX is turbo of coz it will lost hp big time if you run 87.

Very interesting thread. I use 87 in my 99 rolla but use 91 in my wife's 01 CR-V. Im thinking I should give up on the 91 if it supposedly builds up carbon. Can anyone second this?

The 1zzfe is suppose to use 87 octane, it was built and designed to use that fuel, getting a better octane fuel is just a waste of money and dumb...THATS FOR THE 1ZZFE non-turbo!!!!!! I'm only talking about the 1zzfe......just making that clear before people run their mouth...thanks.

You got that right, some people run their mouth for nothing, despite people being clear....

i believe if you have a Japanese imported 1ZZ, you can use higher grades to get better performance only because Japanese engines were designed for the gas they have in japan, not here in the US. Japanese gas is different than what we have here. I think they have like 102 octane or something for high oct gas. BUT since i'm sure no one has an imported engine, this post doesnt apply to anyone.. haha (i'm bored)...

rollatuner - i just realized your sig pic doesnt have door handles.. hehehe

As for what kind of changes the higher octane gasoline causes, makes ECU work because the ECU has to adjust to the different gasoline, and there's other things but is it worth paying $3.60 for a gallon of 97 octane when your car runs best with 87 Octane??....The 2hp difference doesnt justify the cost to me.....

100+ F is so hot! In hotter weather, you will need higher octane gas.
Since the weather is so hot there, your engine might ping with 87. Our 1zz engine has the anti-knock system (I forgot the name, something like that) , so it will adjust the ignition timing to avoid ping. That's why the performance will drop.

here in cali when it gets 100+ degrees, i like to put in higher octane. with 87, i get sluggish response but with higher octane, I gain back slightly more power going up hills and I can blast my AC and still get the same gas mileage. I dont know why. If anyone knows the answer, please do tell.

Its ok. I didn't take any offense to it.

right except for ,lowest octane without pinging , the most power. that simple.