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Model specific boards => Golf mk2 => Topic started by: twistedblack69 on 11 August 2010, 14:47
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Hey guys, know this has probably been asked, I tried the search function but nothing came up. Just been reading through the "fuel" thread in the tech section and apparently Shell is crap :s was thinking of going from 95 to 97oct, but now am thinking of going to Texaco as apparently they're the best fuel, what do you guys think?
Also, can I just put in the 97 octane with a bit of 95 still in there?
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Doesn't matter, ECU will automatically account for whichever octane rating you put in.
The benefits between 95-97 now are so minute that tbh I would just stick with whatever is cheapest.
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Is it 95 or 98? Reading back through my post, 97 doesn't sound right. I mean whatever Shell Vpower is?
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95 +/- .2 ron is normal fuel
97+/- .2 ron is super
100+/- .2 ron is super duper (normally bp i think)
So fuel qualities are a bit spurious. In our engines the noticable differences are so few and far between that in all honesty besides the better mpg there will be little difference.
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Well that's another thing I'm trying to figure out, will the better MPG be worth the higher price?
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It depends on how you use the car. If you are feather light on the throttle, then aye, perhaps paying that bit extra will pay dividends in regards to mpg.
If you are like a wannabe F1 driver, then no, it won't.
Undoubtedly there are going to be people that come on here a bit later, and claim the world of how 97+ Ron has unleased a gazillion horsepower from their engine. I would call it a more placebo effect, especially after playing with fuel RON ratings over the last few years.
As I said, if it's put in yours then the engine will retard* the timing of SOI which will save you fuel, as it will not need as much to enact the same burn, it will burn cleaner, and maybe just maybe unleash a couple of ponies, but only at the top end of the scale.
*Edit: I re-read this and to make it clear - In terms of retarding, that is retarding back to the TDC from the SOI generally SOI is measured in negative degrees so if SOI is 4BTDC retarding it will bring it to 2BTDC.
** TDC - TOP DEAD CENTRE
SOI - START OF INJECTION
BTDC - BEFORE TOP DEAD CENTRE
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Thanx for that :) explained perfectly (and I usually have trouble understanding things like this :)
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On a private road, my 16v Kjet will top out at an indicated speedo reading of 128mph, on regular Shell unleaded, however the same run, on a tank full of Shell V Power, will allow the car to reach 139mph, again speedo readings at that speed are not that accurate, but a marked difference is indicated... i constantly run the car on V Power
Thom
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In my experience running on 97-99RON fuel does make a significant difference to performance, too.
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I run one tank on 97 Ron, and then one on 95 Ron... In Both Cars My Audi S2 & GTI
I really can't say that it make's that much of a differance to performance...
But I was always lead to believe that running the higher spec petrol was & is in the LONG term better for the engine as in its life and less carbon build up... Maybe just an Urban Myth but I stick to it...
Also opening up that throttle from time to time helps to keep the carbon at bay... (apple a day keeps the doc away - etc etc)...
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Deffo not a placebo effect for me. My car is a lot flatter on 95ron, so its always 97 for me .. Revs a lot more freely.
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with my 16v when cold mine never showed any differance or on cold damp day it go exactly the same with normal or super, but on a hot day haveing a prolonged hard booting session it was defanatly quicker and more responsive on 97-99.
with the carbed 8v's it never made any differance to them, with the 8v gti's i had 3 of them each one had diffrent fuel tastes. one chouldn't care what you ran it on. 2nd seemed to feel marginaly better but din't go faster on 97. the 3rd gti was a 97 hoar it ran crap on 95 and sweet on 97
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^^ Must be subjective then, so many variables that could be affecting the fuelling I guess!
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On a private road, my 16v Kjet will top out at an indicated speedo reading of 128mph, on regular Shell unleaded, however the same run, on a tank full of Shell V Power, will allow the car to reach 139mph, again speedo readings at that speed are not that accurate, but a marked difference is indicated... i constantly run the car on V Power
Thom
I think that's all the answer you need right there. :smiley: