super unleaded making a difference?

[deian]

Hi all,

is it me or does my car run better on superunleaded compared to regular unleaded...

what makes a car run better on unleaded... timing adjustments? i put mine forward a bit ages ago to make it better due to the crapy throttle body (it worked for me).

but does the micra run better on superunleaded?

thanks

 

[MSG2]

super unleaded is a higher octane fuel, so its tolerenec to detonation is higher, detonation is very harmfull to all engines, a detonation occurs mainly due to the ignition timing being advanced too much.

The timing advancement occurs and is controlled by the ecu as the engine revs higher and higher, so with higher engine revs the degree of advancement increases automatically by the ecu,
but the ecu stops the degree of ignition timing advancement just short of a detonations occuring.

The ecu knows at what degree of advancement does the detonation occurs as most engines now use a detonation sensors that tells the ecu when this starts to occur, so in other words the ecu will try and keep as much degree of advancement of timing until it is just short of detonation.

you will get more power from your engine with more ignition advancement, so with the super unleaded fuel which has a higher resitance to detonation allows the ecu to advance your ignition timing a little extra than when using ordinary unleaded fuel, so this extra advancement in timing has resulted in some extra power. Got it!!

 

[squarepants]

better for JDM cars as the japs fuel is a 100 ron...super unleaded is 95 iirc maybe higher.

tbh i dont think it makes a noticeable diffrance on the micra, just more expensive lol

 

[MSG2]

yes I have never seen any noticable increase in the performance on my Calibra, in most cases its just you are throwing money away.

 

[ollyc98]

In my car I noticed no difference, in my bike there was a serious increase in power and economy

 

[deian]

my timing isn't automatic, it's the early k11 with manual timing adjustment where you twist the dizzycap/coil unit.

 

[MSG2]

my timing isn't automatic, it's the early k11 with manual timing adjustment where you twist the dizzycap/coil unit.

Got you now, so it may be a placeibo effect (spellings)

 

[Paul Smith]

I've never tried it in a bike?

I find the 97 super from sainsburys seems to work the nicest with my car, the 99 from tesco seems a bit to much?

Thats what i've found

 

[Ed]

Super unleaded on a K11 is a waste (and a K10), the compression ratio and combustion pressures are too low to make any use of it.

Ed

super unleaded is a higher octane fuel, so its tolerenec to detonation is higher, detonation is very harmfull to all engines, a detonation occurs mainly due to the ignition timing being advanced too much.

The timing advancement occurs and is controlled by the ecu as the engine revs higher and higher, so with higher engine revs the degree of advancement increases automatically by the ecu,
but the ecu stops the degree of ignition timing advancement just short of a detonations occuring.

The ecu knows at what degree of advancement does the detonation occurs as most engines now use a detonation sensors that tells the ecu when this starts to occur, so in other words the ecu will try and keep as much degree of advancement of timing until it is just short of detonation.

you will get more power from your engine with more ignition advancement, so with the super unleaded fuel which has a higher resitance to detonation allows the ecu to advance your ignition timing a little extra than when using ordinary unleaded fuel, so this extra advancement in timing has resulted in some extra power. Got it!!

MSG, sounds like you have quoted a generic source of info as none of that applies to the K11, there is no knock feedback. Search for some of my previous posts on K11 timing maps/posts and you may learn something a bit more specific.