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Hi,

I have a Stock R34 GT-R and I put 20L of Caltex Vortex Premium by accident (which has a octane rating of 95) when I should have filled with Vortex Premium 98. This happened because there was no Shell V-Power left at the Shell servo so I decided to use Caltex for the first time and I thought Vortex Premuim was their 98 octane rating fuel.

So my question is this, do I have to empty the fuel tank of all the current fuel ASAP to avoid damage or can I get away with using this fuel (not driving hard) until it runs out and then fill up with the 98 octane rating fuel.

Thanks,

Glen

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with the std ecu it has maps based on 98 RON fuel

now that the user has put in penis fuel (95 ron) the timing will be too advanced so it will combust without spark - detonate / knock

this in turn will tell the ECU its knocking (assuming stock ecu) and the ECU will drop the low octane map

its still bad for the engine and i wouldnt load it up on purpose with penis fuel in it

the stock ECU has no idea (or any ecu for that matter) what octane fuel is being used

all it does is watch the knock sensors for detonation, once it seems certain levels of detonation

it assumes penis fuel is in use and drops back to low octane maps, which basically have retarded timing on them

this makes the car not detonate as the timing is very relaxed and makes the car doughy and flat

yes so in summary

your options now that you have put penis fuel in the tank

1) drain the tank and put high octane in it

2) baby it around and then put high octane in once empty

3) use octane booster and baby it around a little - i would still avoid full loading it up

it will never detonate on light cruise / crusing at 100kmh in 5th or 6th

if its going to detonate with penis fuel, it will be when its ramping on boost or on full load

this is because the engine is under load, and has much more aggressive timing

I wouldn't use octane boost .. I'd rather not have that in my motor after seeing the dirty stains it left through my last GTR's head. Maybe its just cosmetic but even so.

The 34 GTR stock ECU will probably pull timing on you even when you are driving around normally. When I had even a slightly bad batch of 98 in my 34 it would pull timing quickly after driving for a little while and would leave it retarded until you switched the car off and back on. This happened more than once so i correlated the occasions to a particular servo and avoided that from then on.

Don't load it up and fill the tank with better fuel when you can next.

if u want to use octane booster...why not use snake oil, it will have better effects :P

http://au.youtube.com/watch?v=2jbcCr2ll3c

octane boosters do shit all. put that money into an extra 5ltrs of 98 :)

I dont know what you guys are talkin' bout. has anyone actually done it and had problems???? I assume it would if you are running a massive setup, but for basically stock applications it is fine. I have done it to trial different things to my car (I didn't drive it any different - still flogging the guts thru it) and it did nothing... Think... Its 3 octane different out of 95-98.

Don't be worried mate, if you want to be careful, just don't flog it too much. :(

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