will a wrx/sti run ok on 95 ron?
19 August 2012, 09:33 PM
#121
Ffs, heres my view even though people think im a newbie and thick.
From what i know and have learnt...
A uk WRX can run on 95..... BUT a uk STI should only be run on 98 its as simple as that!
I have a WRX on a 55 plate and on the fuel cap it says 98 although mines mapped for 99. As mine was a 225 version standard maybe thats why it says 98 on fuel cap althouth the earlier powered wrx cars may have a less ron advised, i cant answer that.
So im with tony on this as he clearly states that STIs have to be 98ron and WRX can be 95-97 unless its modified.
From what i know and have learnt...
A uk WRX can run on 95..... BUT a uk STI should only be run on 98 its as simple as that!
I have a WRX on a 55 plate and on the fuel cap it says 98 although mines mapped for 99. As mine was a 225 version standard maybe thats why it says 98 on fuel cap althouth the earlier powered wrx cars may have a less ron advised, i cant answer that.
So im with tony on this as he clearly states that STIs have to be 98ron and WRX can be 95-97 unless its modified.
19 August 2012, 09:38 PM
#124
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the dealership owns a forecourt,theyve never sold high oct.....I also had a friend who ran a 2000 turbo on 4 star at times lol
Last edited by Busterbulldog; 19 August 2012 at 09:40 PM. Reason: shonky spelling
19 August 2012, 09:57 PM
#127
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Can you even describe what det/pinking sounds like ? have you ever seen pistons that have been subjected to det and failed, can you tell the differance between a piston fail from det or running lean ?
please forward your answers to
TurdyBums@iknownothing.com
19 August 2012, 10:14 PM
#128
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Having said all this, the only thing saving you above about 6krpm is the learned values, feed back and rough correction disabled above that rpm......discuss!
Last edited by bluenose172; 19 August 2012 at 10:15 PM.
19 August 2012, 10:15 PM
#129
Ok but you are
Can you even describe what det/pinking sounds like ? have you ever seen pistons that have been subjected to det and failed, can you tell the differance between a piston fail from det or running lean ?
please forward your answers to
TurdyBums@iknownothing.com
Can you even describe what det/pinking sounds like ? have you ever seen pistons that have been subjected to det and failed, can you tell the differance between a piston fail from det or running lean ?
please forward your answers to
TurdyBums@iknownothing.com
19 August 2012, 10:33 PM
#137
my opinion is this.
if you have the money to buy mod and run an sti why risk putting crap fuel in it to save a few quid??
it may be ok as the ecu will retard the ignition but the biggest retard in the equation is the one holding the 95 ron fuel pump
if you have the money to buy mod and run an sti why risk putting crap fuel in it to save a few quid??
it may be ok as the ecu will retard the ignition but the biggest retard in the equation is the one holding the 95 ron fuel pump
31 March 2013, 01:46 PM
#145
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i have a 03 sti and i run it on 95 ron with 5% methanol, it made slightly better quality fuel for mapping than 99 ron, and that came from andy forrest, car runs like a dream
31 March 2013, 02:14 PM
#146
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Quite often the higher octane fuel has a lower calorific value than the lower octane fuel. Now couple that with the lower calorific value of the meth your adding may explain why you got better results mixing meth with 95ron. The meth will give you the det resistance anyway.
31 March 2013, 11:13 PM
#147
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The guy who I bought my 03 sti from said its fine to run on any type of super unleaded (most are 97-98 Ron around my way)... I either fill up using Tesco 99 Ron or Sainsburys 97 Ron?! Is 97 Ron a no-no then? And yes I know it says to use 98+
31 March 2013, 11:24 PM
#148
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Depends how much you love your car.If you drive off boost 97ron should be fine. Your ecu should pull the timing back if it hears detonation. Trouble is it only pulls it back once det has occurred so you have already hurt your engine to some degree. Its better to run on 97 than 95 but 99ron is really what you should be putting in. Octane booster works supposedly but they damage your cat after a while. If getting 99ron is a problem where you are you can always get a mapper to tweak your map to run on 97 or even 95ron. As i said tho, depends on how much you love your car.
01 April 2013, 12:09 AM
#149
If it helps please see here
https://www.scoobynet.com/828990-200...ilures-34.html
It's on page 34 post 1005 is from the owners manual and post 1006 is from a tuner who has nothing to gain by talking about fuel. A mapper told me the same so that's good enough for me
https://www.scoobynet.com/828990-200...ilures-34.html
It's on page 34 post 1005 is from the owners manual and post 1006 is from a tuner who has nothing to gain by talking about fuel. A mapper told me the same so that's good enough for me
01 April 2013, 11:53 AM
#150
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Blah Blah, This thread is getting caught up in Ego bashing and ***** waving right now.
Let's stop this and just summarise all the crap with some cold simple facts.
ANY modern car comes with an ECU that will use the sensors and particularly the Oxygen sensors to determine mixture, A/F ratios and ignition timing. They start with a base map and modify from there to get the best A/F ratio they can.
However. Many manufacturers base map is based on 95RON petrol for UK or Euro spec cars and the car may retard ignition or richen fuel ratios from there, but will not advance beyond the base setting, i.e. there will be no benefit to using 97RON fuel.
The cars have knock sensors to detect detenation and retard to protec the engine.
Nissan Micra's do this, Kia's, Vauxhalls and Mercedes. Our Subaru's are no different in this respect except for the base map on a Subaru imported to the UK is set to 98RON. Subaru chose to do this.
Your ECU cannot know what fuel you have put in, it will aim for the correct A/F and ignition for it's map which should give you the book performance. However, it needs to detect the knock to correct for it. You therefore WILL GET DETENATION if you use 95RON fuel.
Of course, once this happens a few times, the ECU will then retard the ignition and remember the new settings. Now you get less power and no more detentaion. However, switching back to 98RON fuel will now not give you the original performance until the ECU is reset. Even a ful STI can therefore run happily on 95RON forever more. It will however have tax and insurance for an STi and run like a WRX.
A Mapped car will have that base level set for the particular engine, removing some of Subaru's cautiousness and generalisation, as each engine is slightly different.
However, the programming for the Knock detection and correction is still there in the ECU and it will retard as before when it detects knock. Of course, if it knocks with much higher temps and pressures than before, it may cause damage before the ECU can react.
There is another way.......to avoid knock and detenation on 95RON, don't rev it and don't use full boost. Disconnect the 3 way (with car turned off) and you get lower softer boost and avoid the knock until you can refill with 98RON fuel.
i.e. DRIVE GENTLY!!!!!
Fuel burns at a rate of 60ft per second. From the plug, it will burn progressively across the piston crown building pressure on the piston and building pressure as a result of increased temperature of the gas. This progressive pressure rise allows for the piston to rise over TDC and start to come down to a point where the pressure can be applied eficiently to the rod and crank. Detenation is where the high pressure and temperature of the air/fuel mixture is ignited early be a hot spot in the combustion chamber and literally explodes causing a sudden pressure/temperature rise too soon. As ignition may be 30 or so degrees prior to TDC, the result will apply pressure down to the crank too early, and the piston will not react meaning it is stuck at TDC with higher temperature and pressure than it was designed for....result is localised heating and shock loading that can cause failure.
This then causes Tony Burns to say I told you so and jump up and down smiling......
Let's stop this and just summarise all the crap with some cold simple facts.
ANY modern car comes with an ECU that will use the sensors and particularly the Oxygen sensors to determine mixture, A/F ratios and ignition timing. They start with a base map and modify from there to get the best A/F ratio they can.
However. Many manufacturers base map is based on 95RON petrol for UK or Euro spec cars and the car may retard ignition or richen fuel ratios from there, but will not advance beyond the base setting, i.e. there will be no benefit to using 97RON fuel.
The cars have knock sensors to detect detenation and retard to protec the engine.
Nissan Micra's do this, Kia's, Vauxhalls and Mercedes. Our Subaru's are no different in this respect except for the base map on a Subaru imported to the UK is set to 98RON. Subaru chose to do this.
Your ECU cannot know what fuel you have put in, it will aim for the correct A/F and ignition for it's map which should give you the book performance. However, it needs to detect the knock to correct for it. You therefore WILL GET DETENATION if you use 95RON fuel.
Of course, once this happens a few times, the ECU will then retard the ignition and remember the new settings. Now you get less power and no more detentaion. However, switching back to 98RON fuel will now not give you the original performance until the ECU is reset. Even a ful STI can therefore run happily on 95RON forever more. It will however have tax and insurance for an STi and run like a WRX.
A Mapped car will have that base level set for the particular engine, removing some of Subaru's cautiousness and generalisation, as each engine is slightly different.
However, the programming for the Knock detection and correction is still there in the ECU and it will retard as before when it detects knock. Of course, if it knocks with much higher temps and pressures than before, it may cause damage before the ECU can react.
There is another way.......to avoid knock and detenation on 95RON, don't rev it and don't use full boost. Disconnect the 3 way (with car turned off) and you get lower softer boost and avoid the knock until you can refill with 98RON fuel.
i.e. DRIVE GENTLY!!!!!
Fuel burns at a rate of 60ft per second. From the plug, it will burn progressively across the piston crown building pressure on the piston and building pressure as a result of increased temperature of the gas. This progressive pressure rise allows for the piston to rise over TDC and start to come down to a point where the pressure can be applied eficiently to the rod and crank. Detenation is where the high pressure and temperature of the air/fuel mixture is ignited early be a hot spot in the combustion chamber and literally explodes causing a sudden pressure/temperature rise too soon. As ignition may be 30 or so degrees prior to TDC, the result will apply pressure down to the crank too early, and the piston will not react meaning it is stuck at TDC with higher temperature and pressure than it was designed for....result is localised heating and shock loading that can cause failure.
This then causes Tony Burns to say I told you so and jump up and down smiling......