Switched to 91 octane...

[mikejungle]

So I put in some 91 octane fuel in my eta last night to get my car ready for a chip that I plan on purchasing today or tomorrow.

I've read people saying that it's not necessary in an unchipped car...and I don't know if it's just the placebo effect hitting me, but the car seemed to drive noticeably smoother.

Am I imagining things or could there have been a noticeable difference?

[redhatpat]

You're imagining things. You'e probably lost some torque/horsepower.

[Sagaris]

Your best performance comes from running the lowest octane fuel possible that your engine can be run hard on and not auto-ignite.

[TurboJake]

I promise you that your going insane, and buying into ricer talk of octane increasing performance without the tune.
Kill it before it grabs hold you. get that chip in there STAT.

[Evan12]

Ive heard the same. Going Higher octane without chip or tune doesnt increase performance, and can actually be worse.

[mikejungle]

Sorry if I came off stupider than I meant to, but I never mentioned anything about it feeling stronger or like it performed better.

I just thought it felt smoother. Like i said, that could be in my head, so I was looking for any rational explanation.

[MikeDE]

Sorry if I came off stupider than I meant to, but I never mentioned anything about it feeling stronger or like it performed better.

I just thought it felt smoother. Like i said, that could be in my head, so I was looking for any rational explanation.

It's ok, it's the Honda Effect: If it sounds & feels faster, than it must be.

[blefevre]

If your car was pinging then yes, a higher octane could help it run smoother.

[TurboJake]

Does the 91 around you lack the ethanol that's in lower blends?
That can do it, for sure.

[mikejungle]

It was from chevron, so maybe that's it.

[Evan12]

Duh! Chevron has techron!

[warmseth]

You're imagining things. You'e probably lost some torque/horsepower.

Correct. Lower octane is actually MORE explosive and thereby has more potential for power. Octane is a predetonation restricter that reduces power somewhat but is necessary at higher pressures to not thrash your motor. The thought that one ought to run the lowest octane before you hear pinging is correct.

[immajackuup]

http://www.m42club.com/forums/showthread.php?t=5569&page=3

[nomansland92]

Correct. Lower octane is actually MORE explosive and thereby has more potential for power. Octane is a predetonation restricter that reduces power somewhat but is necessary at higher pressures to not thrash your motor. The thought that one ought to run the lowest octane before you hear pinging is correct.

thats pretty interesting, good to know these kind if tips ;)

[nrubenstein]

However, old ass engines with hot spots may want higher octane than they did when new. It is possible that the car is running better. It's also entirely possible that it's 100% placebo.