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Old 01-10-2015, 05:18 PM
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RJ999 RJ999 is offline
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Quote:
Originally Posted by Rossco View Post
RJ, Pure ethanol (E100%) has a RON rating of 108.6.

Have you not noticed the the 107 OCTANE bowsers do not have '107RON' written anywhere on them?
Australia uses 'Research Octane Rating' to label fuels - not 'Octane'.....

But you've missed the point - The octane rating of E85 is in the region of 105(+/-), but when combined with its cooling properties, the actual knock resistance of E85 is much higher than the RON rating would suggest, it's nothing like 95 v's 98 - the fuels behave completely differently inside your motor.

In plain English this means that when E85 is injected into the engine, it goes through a phase change from liquid to gas and during this process it absorbs a lot of heat from the intake charge. A colder intake charge is denser and improves power, but also has the effect of making the engine far less prone to detonation..... Unless your tuner is a muppet.

Stop stressing about 'E85' ethanol content.........You're on a witch hunt.......... all you're doing is showing your lack of understanding on the subject.

Remember United's P100? Well that was simply 98RON with 10% ethanol.

TL;DR: As was mentioned already there is very little difference in the detonation resistance of e70 and e85. The difference is less than one octane point. In other words, don't sweat the difference.
OK that makes sense and good to know that its nothing to worry much about...I won't stop using osborne park but I'll still go fill at gnangara or padbury before a track day as the fuel seems to keep better there as proven.
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06 STi: 337hp @23psi on E85...
06 STi: 309hp @22psi on 98ron...
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