Unleaded Regular

[nic]

What is the octane value for "unleaded regular"?

In US it seems to be 87 octane.

In Singapore... it is 92 or 95?
definitely not 98/V-power.

[mave]

I believe it is 95. there is still 92, but it is getting uncommon. Esso or Bp may have it.

[nic]

thanks.. found the answer at wikipedia:

Different countries have some variation in what RON (Research Octane Number) is standard for gasoline, or petrol. In the UK, ordinary regular unleaded petrol is 91 RON (not commonly available), premium unleaded petrol is always 95 RON, and super unleaded is usually 97-98 RON. However both Shell and BP produce fuel at 102 RON for cars with hi-performance engines. In the US, octane ratings in fuels can vary between 86-87 AKI (91-92 RON) for regular, through 89-90 (94-95) for mid-grade (European Premium), up to 90-94 (RON 95-99) for premium unleaded or E10 (Super in Europe)

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And also read this interesting comment there and several other sites:

A high octane fuel such as LPG has a lower energy content than lower octane gasoline, resulting in an overall lower power output at the regular compression ratio an engine ran at on gasoline. However, with an engine tuned to the use of LPG (ie. via higher compression ratios such as 12:1 instead of 8:1), this lower power output can be overcome. This is because higher-octane fuels allow for a higher compression ratio - this means less space in a cylinder on its combustion stroke, hence a higher cylinder temperature which improves efficiency according to Carnot's theorem, along with less wasted hydrocarbons (therefore less pollution and wasted energy), bringing higher power levels coupled with less pollution overall because of the greater efficiency.

It seems we get "more energy" by paying "less".
But, in terms of efficiency, we get "more efficient" by "paying more"