Yaris vibration abnormality

[YarisSedan]

Originally Posted by Kaotic Lazagna

I use the highest octane (premium, 91 here; regular is 87) once a month or two since it has a higher concentrate of detergent of the gas brand that I use (Chevron) for cleaning purposes. I see, and didn't expect, a boost in power. I do, however get WORSE gas mileage when I use premium.

Its a common misconception, a lot of people do use premium once and awhile for the same reasoning but there is no additional additives in premium gas then you get with regular gas. Its better to just stop by your local parts store and buy a bottle of chevron techron fuel injector cleaner and adding that to your gas tank. A lot of times they are on sale and for a few dollars which is what your are going to be spending on 91 octane anyways

As long as you use a top tier gas you should be fine

http://www.toptiergas.com/

Ive recently switched from chevron back to 76 gas they have 3 times the amount detergant additives of the minimum required by the EPA and 30 percent more than the top tier standard