Honda typically recommends "regular" gas. They give min octane number recomendation, which is kind of useless in Canada, where the numbers at the gas stations are somewhat different, an average of two values I believe. Bottom line, the cheap stuff is fine.

The higher octanes are for higher compression engines, and the HCHII definitely is not high compression ratio. The only value of higher octane is improved ability to resist exploding.

In other words, the higher octane stuff is harder to ignite, which is of value in high compression engines where glowing carbon deposits might pre-ignite the fuel/air mix before it's meant to be ingnited by the spark plugs, causing the "pinging" sound. This is most likely to occur under heavy load, say going up a steep hill.

Considering the number of cars that actually need higher octane, there's an inordinate number of pumps offering it.

 

...

The Hybrids compression ratio is 10.8 to 1 and that is a high compression motor.

 

Not high enough to require premium gas though.