octane?

[SMOKEY53]

Slightly OT (only because in Australia we have different octane ratings) but here is a real world test done by running 3 identical vehicles on 3 different fuels - E85, E10 and PULP (98 octane). The vehicle is specified by the manufacturer to run on regular (91 RON), it is the most 'average' car in Australia, but has an engine that can adjust timing and fuel delivery cycles for different fuels - so this shows what happens when you put non-specified fuels in, and how the engine responds in real world conditions.

Ethanol put to the test: E85 v E10 v premium unleaded

You'll have to change your mindset to understand our L/100km measure of economy, and our different octane rating.....and then stop yourself falling off your chair when you see what we pay for fuel. But......overall, if you skip to the summary of the article.....


Even though the car with the cheapest fuel returned the worst economy figures (used most fuel, ran for less kms) it was still the cheapest to run.

But if your main goal is to achieve best performance, fill up less often, and protect your engine (with 'additives') then premium is the best choice for both around town and on the freeway.

[JCL]

Originally Posted by SMOKEY53

Slightly OT (only because in Australia we have different octane ratings)...

AKI is simply an average of RON and MON. Two different single cylinder test engine protocols.

There is around 6 or 7 points difference from RON to AKI, but it isn't linear or exact.

98 RON is pretty close to 91 or 92 AKI
95 RON is what we call midgrade, or 89 AKI
91 RON is pretty close to 87 AKI

And ethanol screws them all up.