91 Grade fuel?

[codymclelland]

A friend of mine decided to try putting 91 grade fuel in his Jetta that is graded at 87. After about 20 miles, the computer adapted and the timing advanced and now it roars! Would the same be true of the Yaris? Would the computer adapt or would this somehow be bad for the engine?

[1NZYaris1]

some say yes and others say no , me i say yes it will and does ,
but i only have a 1.3 not the 1.5so try it and see.

[severous01]

umm....no

simple fact that the ecm controls the timing, not the fuel. timing is pre-determined to be whatever manufacture programmed into the ecm. the one and ONLY thing that will change the timing other than throttle is the knock sensor. and this will retard timing, not advance.

now...if you have a programmer, that's a different story because you're changing ecm programming.

you need to do a wiki search on octane or fuel ratings. grade of fuel does nothing unless you're supposed to be runnin 91+ and ur not.

[Kaotic Lazagna]

Nope, it won't. I try to run premium (Chevron) at least once a month for cleaning purposes. Never noticed any changes in performance. Simple fact is that if your car can't appreciate the added octane, it won't do anything with it.

[battleversiontc]

i run 91 in my tc and its rated for 87 and it actually runs better on 91 then on 87 same as my yaris i run 91 on it to it runs better then on 87 it does help a little bit and it does change anything better gas does make a difference but a very little difference but some notice it some dont

[Deltasix]

Originally Posted by Kaotic Lazagna

Nope, it won't. I try to run premium (Chevron) at least once a month for cleaning purposes.

Do you have any info to back up the fact that this actually cleans out the system? Just wondering, because I've seen a lot to the contrary.

As to the original question, I've filled my tank up with 93, no difference whatsoever.

[Kaotic Lazagna]

Originally Posted by Deltasix

Do you have any info to back up the fact that this actually cleans out the system? Just wondering, because I've seen a lot to the contrary.

As to the original question, I've filled my tank up with 93, no difference whatsoever.

I actually don't, I'm just going by brand name (I did an experiment with Safeway vs Chevron with my GTI, but using 87 for both, and got horrendous FE with Safeway). But then, there are my Suby friends who swear against Chevron because it actually messed up their engines. Who knows, may be those "cleaning additives" in Chevron are bad for boxer engines?

[Aothachos]

omg this was posted in general which one to use 91 or 87 lol i use 91 all the time hands down

[severous01]

Originally Posted by battleversiontc

i run 91 in my tc and its rated for 87 and it actually runs better on 91 then on 87 same as my yaris i run 91 on it to it runs better then on 87 it does help a little bit and it does change anything better gas does make a difference but a very little difference but some notice it some dont

it's all in your head or you got problems that need to be fixed with pre-ignition...or knock


read:
http://en.wikipedia.org/wiki/Octane_rating

http://www.answers.com/topic/octane-rating-1

http://www.associatedcontent.com/art...ly.html?cat=27

http://www.rpmeng.com/octane.htm

[battleversiontc]

can you prove it not unless theres a dyno chart plotting two different octanes then all the words that someone writes just means bullsh!t to me not unless is proven in numbers on the same car with a base of 87 octane. and it aint in my head the cars performance is better and im know for a fact i dont have problems with my tc or the yaris. if a car that is rated for 91 octane puts 87 octane in there is a performance decrease as well as knock but the knock sensor will pick that up and the ecu will adjust timing to prevent the knock so there for 87 octane upgrading to 91 octane in a car rated for 87 performance will increase such as accleration because timing will then advance as the sensors will adjust to the change of the c02 levels in the exhaust there for increasing performance. if there was no need for higher octanes we wouldnt need em and every car would use the same octane waste money and time to develop different octanes if thats the cause its all in my head sorry maybe you just getting alittle to much sun in texas

[Kaotic Lazagna]

Here you go: http://www.youtube.com/watch?v=dDHwC...eature=related

Very good experiment comparing different octanes, and proof that premium gas will not gain you anything in terms of performance.

[battleversiontc]

if you watched the very end portion he did say that higher octane will give you more performance and 1 out of three cars never made performance so you just proved me right

[Kaotic Lazagna]

Originally Posted by battleversiontc

wheres the proof when two of those cars are turbod and they made more horsepower on higher octane then reccomended so you just proved me right

Yeah, but our Yarii (at least mine) are not force fed. It would fall under the same category as the Clio, purely made for economy. "You guessed it, 81 brake horsepower."

I was never claiming that premium gas will not make any difference on higher end, performance oriented cars. But suit yourself, keep spending more for premium gas. And if you really want to prove us wrong, conduct the same test that they did.

[Kaotic Lazagna]

Originally Posted by battleversiontc

if you watched the very end portion he did say that higher octane will give you more performance and 1 out of three cars never made performance so you just proved me right

Yeah, those other cars are PERFORMANCE cars, not economical cars. I don't know about you, but I don't consider our Yarii performance cars. We're basing this thread on the Yaris, an economical car. And as in that video, the economical car did not make extra power with higher octane gas, so you're proving me right.

[Kaotic Lazagna]

http://www.yarisworld.com/forums/sho...hlight=premium

[Kaotic Lazagna]

But hey, it's not our money. Do what you like. If you feel a performance gain, good for you.

[battleversiontc]

ok try a different na make that are economy friendly then to prove me wrong cause one car from a different make doesnt do you know good in here find one with a yaris in it then post it other then that dont compare cars to another cause there just not the same. fine you didnt prove me worng or right. but not unless you come across a yaris video since thats what its based on then dont say nothing until you can prove me wrong or right

[Kaotic Lazagna]

Originally Posted by battleversiontc

ok try a different na make that are economy friendly then to prove me wrong cause one car from a different make doesnt do you know good in here find one with a yaris in it then post it other then that dont compare cars to another cause there just not the same. fine you didnt prove me worng or right. but not unless you come across a yaris video since thats what its based on then dont say nothing until you can prove me wrong or right

Same can be said with you. Find a video saying that higher octane gas on a Yaris will increase its performance.