jermcruz

i agree. the car isn't shakey when it idles when it's cold when i use 91.

yes, i've read all the threads on this when they pop up. so i've tried all 87, 89, and 91 octanes, on shell, chevron, and mobile (waiting till the gas light comes on). multiple times i might add. overall, the brands are pretty much the same. the only thing i have over complete stock is the trd exhaust, if that makes any difference at all.

ok here's the debatable part: with the 91 gas, i do feel the engine idle a lot smoother, and i do feel more of a reaction on the throttle. so overall the engine feels smoother coming off of first and when shifting gears. don't get me wrong, there's no change in performance or any significant gains, not even an increase in gas mileage.

what made me experiment all this? well, my brother has a tc as well. i got mine in january, he got is in febuary. and he uses 91. wondering why, i decided to compare. i drove my car around with 87 gas. then i drove his around the same route. it does feel different.

how do i know it's not just my imagination? my uncle, a car enthusiest himself, test drove my car to see how good it is. a week later, he test drove my brother's car. And he noticed a difference. he asked my brother "why does your car feel different than your brothers" and he told him, "we're guessing it might be the gas." my uncle did not know what kind of gas we used, nor did we know he drove both our cars. how can it be his imagination?

so that's MY observations. If you REALLY want to know, you gotta go out and try it. you may even get different results than me. i don't think price should be an excuse. you're already paying 30 bucks for a full tank of 87, i'm sure you can affford 33 bucks for premium.

Darkness

I heard something about how using a higher octane gas can damage the car because since it's made to be more compressed, with just a stock (no FI) engine then the higher octane gas will leave more carbon deposites in the engine causeing damage to the internals

gs_is

Shoot, I wish my cars could run on regular!!! HAVE to fill in premium cuz of the higher compression of the Toyota inline 6's.

If I didn't need to, I'd never waste my $$$ on premium!!

dieselstation

maybe it feels different because your borther's car is automatically adjusting it's timing to adapt to the 91 octane.

there are NO performance benefits to higher octane, and there are no "special" additives to higher octane. it won't make your car run cleaner if you're wondering.

read it from Shell itself. http://www.shell.ca/code/motoring/en...es/octane.html

reagulator

I think that it will leave more carbon deposits because higher octane gas burns slower and longer. that means there will still be a fire and the exhaust stroke and end up cooking the exhaust valve. Dont quote me on that

Rivulent

muhahha! I have quoted!

SCI_TC_GUY

all I know is I use 87 in my tC but my Kaw. ZX-11 has to have 93(what we get)......91 minimum.....

mandos

I use 89..

Why...because I'm in Iowa....and the Ethanol Added=$.10 cheaper/gallon than 87 ;)

AtC2nv

there is noe way that using premium can cause less damage, it has to cause more damage. When i had my maxima a machanic told me not to use premium all then time because it damaged the engine. He said this even tho the car was meant to premium. Let me use this time to clear up a mistake i made in my previous reply in which i said that premium has more hexane. but in reality 91-91 octane actually uses LESS hexaine and more petrolium because its made to be used in higher compression engines.

epitek

i dont understand that... the factory said to use premium, but a mechanic said not to...

umm... i would trust the factory more since they built the engine. if you car had something wrong with it, then fine, the mechanic COULD be right... so what do you mean when you say "even tho the car was meant to premium"? was it stated in the manual? b/c in the tC, in the manual it says 87.

The_Instigator

Premium will leave more carbon deposits in the combustion chamber so after like 75000 miles you may increase your compression ratio a little and make some more horsepower. Thats the only advantage I can come up with...if you can call that an advantage

AtC2nv

i dont understand that... the factory said to use premium, but a mechanic said not to...

umm... i would trust the factory more since they built the engine. if you car had something wrong with it, then fine, the mechanic COULD be right... so what do you mean when you say "even tho the car was meant to premium"? was it stated in the manual? b/c in the tC, in the manual it says 87.[/quote]


"it was meant to use premium"...yeah dawg i said that because thats what nissan said we should use

jrv2000

Let me clear up the whole octane thing.

1. Heptane handles compression poorly = combusts easily
2. Octone handles compression very well = doesn't combust easily
3. 87 octane = 87 percent octane, and 13 percent heptane. (91 octane = 91% octane, 9% heptane)

Daemon1313

If you want to get really technical the number you see on the pump is actually the "anti-knock index". For all the details and more info than you ever wanted on what octane is:
http://www.faqs.org/faqs/autos/gasoline-faq/part3/

Long story short run the type of gas your manual recomends.