Using 92 Octane Instead Of 95 Octane

[The Don]

IIRC 100 is not the ultimate octane (RON) though, it's just better than 98? But I don't think there are many road cars requiring anything above 100. Even 95-100 is required by a handful of models and probably doesn't justify maintaining a separate stock?

I take your point and if only a few cars needed it, it either needs to be sold at a significantly higher price in a few specific sheds or the owners have to adopt other approaches like mixing with toluene or octane booster.

But the unforgivable issue is the inconsistent quality of petrol and their octane rating. The problem is so bad that D*MO at one point instructed their customers to use standard 90 octane petrol rather than 95 as the quality was more consistent. This was of course before the well known fuel debacle of contaminated fuel killing fuel pumps.

[U.T.C Rodrigo]

E

[Twin Turbo]

Unless the manufacturer specifies high octain fuel, no point inn using it.

[aspirinblaze]

My car is a Toyota Yaris Ativ 2018. It's been rated 95 octane. And we fuelled it that until the fuel crisis.  But after the fuel crisis we started fueling 92 cause of a shortage in 95 octane petrol. Is it okay to do so? And does using 92 petrol decrease fuel mileage?  

[iRage]

I am surprised that the Ativ needs 95Oct because the Ativ is a car made for developing country markets. I checked the manual for the Malaysian and Vietnamese equivalent, Toyota Vios; that can  runs on regular gasoline with an octance rating of 87 - 92 (Brazilian variant needs 94 and Argentinian 91, etc..). Where does it state your car needs 95 Oct ? It might be because of the market so it is possible that 95Oct is recommended. The good thing is this also means that your engine can probably handle anything from 87 - 95 Octane fuel.

Does your engine knock ? Pretty much that is the first and foremost sign of whether 92 Oct fuel is bad for the car. If there is no knocking then more than likely your engine is tolerant of 92. You might experience a bit of knocking under load, the user manual says it is normal under load. But if the knocking is persistant, then you need to do something about it. You can always try adding an octane booster. <My guess is that your car will be running okay with 92 Octane. Toyota's standard engines for entry level cars are quite happy with low octane fuels and high octane becomes a must only with the high-end newer engines.