Octane ?

[Ben_]

I experimented with this recent at the auto x. Used premium fuel as opposed to regular I usually run. I noticed quicker throttle response and the engine ran a bit smoother. Maybe it's all in my head. The more experienced users will know if premium fuel will change the timing the ecm gives

[why?]

Originally Posted by albee213

I read some information about the Yaris engine and I found out some interesting stuff.

The engine specs show 10.5 to 1 compression ratio which would mean it should use premium fuel to prevent early detonation.

This engine can use regular fuel do to improved technology in how the fuel is injected and the shape of the combustion chamber prevents pre-ignition of the fuel while squeezing a little bit more power out of the fuel.

After saying that I still use mid or prem due to the high compression ratio of the engine, to each their own.

Originally Posted by Ben_

I experimented with this recent at the auto x. Used premium fuel as opposed to regular I usually run. I noticed quicker throttle response and the engine ran a bit smoother. Maybe it's all in my head. The more experienced users will know if premium fuel will change the timing the ecm gives

Except that is bogus. The computers control the system so much more than 30 years ago. Everything is different and your ideas are just wrong. Toyota recommends 87 and it is a waste of money to run anything else on a near stock engine.

10.5 to 1 is not high compression anymore. There are gas engines that run more easily. Toyota has used this engine in this configuration for at least 20 years, probably longer. It is rock solid with the crappiest gas you can find to put into it.

Higher octane could make the engine run 'smoother' although that in no way equates to making more power or getting better throttle response, especially since the throttle is controlled by a computer.