WHICH octane for VITZ?

[Samm]

????

[Twin Turbo]

An in-depth discussion has been made on local fuel . pls refer older threads.

 

[kush]

10 hours ago, Samm said:

????

What is the engine spec. This most probably UK built

 

[iRage]

Although it is the same car the engine and emission control systems differ (sometimes slightly and sometimes vastly) which in turn suggests the different types of fuel.

Japanese spec Vitz requires regular gasoline which in Japan ranges from 92 - 95 ish depending on the brand...so your Vitz will happily run with any of that....

<yes I have the last bit of the upper sentence stored in my clipboard forever because it seems to come up a lot>

[Hyaenidae]

15 minutes ago, iRage said:

 

Japanese spec Vitz requires regular gasoline which in Japan ranges from 92 - 95 ish depending on the brand...so your Vitz will happily run with any of that....

 

2

Why don't they mention RON/MON on Japanese owner's manuals, all they say is "regular". Is it because there's no significant difference between 92 and 95?

Owners manuals issued for every other region clearly mention the recommended RON.

Edited July 5, 2019 by Hyaenidae

[iRage]

Because in Japan they set it by range....just because they can I suppose....

Not a technical person but you cannot vary the difference between 92 and 95 because that signifies the rate at which the gasoline combusts right ? So if they make it closer that means the 92 becomes a higher octane or the 95 is a lower octane ?

[kush]

39 minutes ago, iRage said:

Because in Japan they set it by range....just because they can I suppose....

Not a technical person but you cannot vary the difference between 92 and 95 because that signifies the rate at which the gasoline combusts right ? So if they make it closer that means the 92 becomes a higher octane or the 95 is a lower octane ?

There is no exact RON number when you say 92 it is generally (90-94) similarly 95 (93-97) so even in 92 it can be 90 or 94 depending on the stock. Modern ignition systems could adjust to these changes up to certain threshold. Issue comes in when you exceed the threshold and engine start knock which is bad.

JDM cars imported to SL are happy with 92 as they are designed to run on "Regular" Japanese fuel.

Any one pumping 95 is just burning their money for nothing.

[gayanath]

A comparison between locally available Octane 92 and 95. (The data is just those published on Ceypetco website and I did only a cut and paste job)

Yellow - Same Property/Test for comparison

Green - Same Specs

** Just for the info....

[iRage]

5 hours ago, kush said:

There is no exact RON number when you say 92 it is generally (90-94) similarly 95 (93-97) so even in 92 it can be 90 or 94 depending on the stock. Modern ignition systems could adjust to these changes up to certain threshold. Issue comes in when you exceed the threshold and engine start knock which is bad.

JDM cars imported to SL are happy with 92 as they are designed to run on "Regular" Japanese fuel.

Any one pumping 95 is just burning their money for nothing.

My point was in a scale the interval between two points is constant. Moving either end point towards each other reducing the interval result in the end point being at a different value of the scale   

[SahanBSB]

Japanese user manual says to use "Unleaded Regular Gasoline".

Wikipedia says 
Japan: Since 1986, "regular" is >=89 RON, and "high octane" is >=96 RON, lead free.

So I think it is safe to use 92.

Edited February 24, 2021 by SahanBSB