I agree with Willie, but would add that the RON value degrades a LOT quicker than you would think.

The degradation is worse on higher octane fuels like Tesco99 and Optimax as the additives required to achieve the higher octane are added post refinement and often just prior to filling up the tanker trucks. These additives are volatile and degrade quickly.

I use Optimax exclusively as there isn't anything else locally and as my car doesn't get used from one weekend to the next, sometimes 2 weeks, I ALWAYS notice this degradation and it feels flat as fook until I top up or use OB (I use Millers CV Turbo).

On fresh petrol and using OB, the car feels so much more smoother in power delivery and seems to negate the effects (to a degree) of heat soak. as DPJ says "A good octane booster will reduce knock and lessen Correction Factors applied to timing by the ECU when the engine is under heavy load." which is why it feels to lessen the effects of heat soak.

if your still filling up with optimax its no wonder its degraded.... must be a year old at least:cartman:
 
Thanks for the replies guys. I have made a couple of tweeks since the last RR (air feed & N249 Bypass) and the booster was the last thing to try, mostly to compare both results side by side I will only get the opportunity to stick some in tomorrow morning so I hope it will still work.
 
Thanks for the replies guys. I have made a couple of tweeks since the last RR (air feed & N249 Bypass) and the booster was the last thing to try, mostly to compare both results side by side I will only get the opportunity to stick some in tomorrow morning so I hope it will still work.

It would be interesting to see a back to back RR comparison but I'm sure someone must have already done it? :)
 
i used to run the stp stuff in my scoob, you can get it from halfords for a fiver and its supposed to treat a whole 60ltr tank. i used it every full tank and swore by it!
 
Well I stuck some Wynns in it (start off small) and there isn't alot of difference but I have only done about 10miles since fill up. I went with Tesco 99ron due to a report that the local Shell garage had some dodgy V-Power, so if the bottle is right and the fuel at Tesco was fresh, I should be running 101RON. I am taking the car to my garage tomorrow to do a couple of bits so i'll test it out on the way. I don't expect a difference now though to be honest as I am sure it'll take a tank full to adapt but perhaps next week or the week after, I'll see some improvements and by that time I should have VCDS :). Keep you posted!
 
Who the hell knows :D but I guess they can't state it increases by 2RON if it doesn't, or at least come close. It smelt strong, that's all I know.

I am just glad to have the old V-Power out and start fresh, it's been running off since last fill up, like it's on 95RON to be honest but it's perked up again today with the new stuff. I'll monitor and see if things improve further + i'm changing the fuel filter tomorrow too.
 
Sorry, I forgot to update. Well yes, it felt smoother, idled smoother and picked up a little quicker. May have been placebo factors though and prior to that, I had crap fuel so anything was an improvement.

I want to do some logs with and without but I am unsure which blocks to use, that way I will know for sure.
 
I have used the octane booster, and yes, through my butt dyno, the car felt definitely quicker

picked up quicker and boost felt like it came in a little harder

however this could have all been in my mind, and my friends also as he tried some in his stg3 ibiza cupra, and reported the same

however, I have only tried it once and as said by others I wouldnt bother doing it for a RR as its not a true reflection for power I run on a daily basis

Also I know Optimax can degrade quickly, but on a positive point, I would only use Optimax as to ensure I have good, clean decent fuel in my car as this is there main business, unlike tescos which main business is selling milk and bread, and not fuel!
 
My mates had modified their GT4's pretty much the same way... they had RR'd their cars previously and had come within a couple of bhp of each other (maybe 5 IIRC) my mate always ribbed my other mate who he had "beaten" on the RR.

So the next time we went up Scott fired in loads of octane booster and ran it on the Dyno after running the car on it for about 100mi (the distance to the RR) - The car car made more power than my other mates car, but not by much! I suppose you can say it doesn't prove anything (and I agree) perhaps the oil needed changed or his tyres needed pumped up, but it made him feel better lol!