Tuning Options

[SirDigby]

Originally Posted by tmontague

Will resetting the Yaris' ECU and running 91 octane for a while cause an increase in performance? Now I know that 91 octane does not give more power over 87 on the same tune, but I am asking because the 1nz ECU is constantly learning.

The 1nz if already a relatively hgh compression engine (10.5:1) and is therefore tuned to reduce knock on 87 pump gas. If you reset and run 91 or even 94 will the knock sensor etc. allow for more advanced timing since there is no detection of knock?

the manual states the optimum fuel to use should have a RON ratting of 91
that being said, if you run on 87 the engine is retarding; even though we use the RONxMON/2 method. but it's still a guess where in the mix you end up. it is acceptable to run on this, but you should buy the highest quality possible. with fuel at or below $2 a gallon for 91, why not.
where I live we also have 85. I KNOW my car came with a full tank of it when I bought it. it took about 3 tanks of 91 to get it running properly. I always run 91. (ethanol-free if I can find it)
people might say it's a waste of money; but if you are going to use synthetic oil, synthetic trans fluid, good tires, and you don't cheap out on the products you use on your car, why would you buy cheap fuel???
duh.