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Discussion Starter · #1 ·
can i run my evo 6 on a full tank of C16 high octane fuel; the octane is 117. if not what is an appropriate mixture ratio with say 97 octane fuel. what are the advantages and disadvantages (if any) of using such high octane fuel. any information is appreciated.
 
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Discussion Starter · #2 ·
how ya doin

There is no reason why you cant use that higher octane.
There are some big benefits you can run higher boost pressure or advance the timming futher more safely without the big worry of detonation

So the higher the octane fuel the better
 
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Discussion Starter · #3 ·
Speed, you can run on the 117 octane OK, but there's probably not much point unless ambient temperatures are very high or you are running high boost.

High octane fuel reduces the likelyhood of the engine to pre-ignition. This will allow the timing to advance to the optimum point for maximum power if it has been retarded by the ECU to supress pre-ignition. Running on 97RON in normal 20'C ambient and standard boost I would not have thought that the ignition would be appreciably retarded. However if the ambient temp is higher or you are racing and getting very high underbonnet temperatures and/or the boost has been increased from standard, the ignition will be retarded. Using high octane fuel at this point will increase power as the ignition will no longer be retarded.

If you need to work out the octane rating of a mix then you can do so based on the proportions of each component. i.e a 50:50 mix of 117:97 octane fuel will give 107 octane fuel. 10:90 mix of 117:97 octane fuel gives 99 octane. Personally I wouldn't go any higher than 99/100 octane unless I were using serious boost (2bar|PLS|), and then its probably easier to use water injection.

High octane fuel does not give more hp on its own, it just allows you to make other modifications to increase power which would otherwise melt the pistons due to pre-ignition.
 
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Discussion Starter · #4 ·
One big problem. C16 is leaded. It will destroy your CAT and 02 sensor. If Antigua is anything like Jamaica you probably dumped the CAT long ago, but 02 sensors don't last long on leaded fuel and are expensive to replace. Out here, people only put in a couple gallons for racing and then syphon it back out of the tank or immediately dilute it with a full tank of unleaded.
 
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Discussion Starter · #5 ·
Very good answer from Oil Goon.

There are cases where upping the Octane of the fuel can actually decrease power.
 
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Discussion Starter · #7 ·
In Jamaica you can buy VP103 which is 99 Octane unleaded. If you can get that it would be better. Easier than mixing fuel and if you mix fuel you will still have some lead content.
 
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